1084 1084-7-OM - RL-2027 [II]- - TECHNICAL REPORT ECOM- 0547.. AZIMUTH AND ELEVATION DIRECTION FINDER 0. INSTRUCTION MANUAL 0... January, 1969 ECOM UNITED STATES ARMY ELECTRONICS COMMAND FORT MONMOUTH, N.J. CONTRACT DA AB07-67-C0547 THE UNIVERSITY OF MICHIGAN DEPARTMENT OF ELECTRICAL ENGINEERING RADIATION LABORATORY ANN ARBOR, MICHIGAN

AZIMUTH AND ELEVATION DIRECTION FINDER INSTRUCTION MANUAL Chapter 1 Chapter 2 Chapter 3 Chapter 4 INTRODUCTION 1.1.0 Scope 1. 2.0 Component Description 1.3.0 System Application 1.4.0 Data Interrupt Pulse Generator INSTALLATION 2.1.0 Selection of Site 2. 2.0 Cabling of the Azimuth - Elevation Direction Finder 2.3.0 Turn-on Procedure for Azimuth - Elevation Direction Finder System 2.4.0 Computer Program Modification COMPUTER INSTRUCTIONS AND TABLES 3.1.0 Teletype Keyboard and Command COMPUTER PROGRAM 4.1.0 Introduction 4. 2.0 General Program Operation 4. 3.0 Initialization 4.4.0 Link 4. 5.0 Teletype Character Processors 4. 6.0 Note on the Tapes Supplied with the System 1 1 3 11 12 14 14 17 20 23 24 24 35 35 35 44 50 53 56 57 100 Assembly Listings Source Tape Listings i

CHAPTER 1 INTRODUCTION 1.1.0 Scope This manual covers i.llstallation and operation instructions for the Azimuth - Elevation Direction Finder. c'I'clllc ialnuallu covering detailed operation and maintenance instructions of several of the components of the Azimuth - Elevation Direction Finder are listed below. Those components not covered by separate manuals will be discussed in this manual. Manual No. Manual Title Manufacturer 1 2 3 4 5 6 7 8 9 10 11 12 13 Antenna Scanning System 450-A Amplifier Memory Voltmeter Model 5201B Model 848 A/D Converter Data 620/I System Reference Manual Data 620/I Maintenance Manual Interface Reference l lManalll Subroutine Descriptions Progralming Reference Manual Fortrandil Reference IatInual Priority Interrupt Module Power Supply Model HW10-8 Operating Instructions Listings S. Sterling Company Hewlett-Packard Micro Instrument Co. Texas Instruments Inc. Varian Data Machines Varian Data Machines Varian Data Machines Varian Data Machines Varian Data Machines Varian Data Machines Varian Data Machines Mid-Eastern Electronics S. Sterling Company 1.1.1 Purpose and Use The Azimuth - Elevation Direction Finder consists of an assembly of equipments for use in the detection, frequency measuremenets and determzination of bearing (azi mullhll and elevation) of radio freqLuen-cy (RF) transmissions from fixed, mo1lbilc, or poLtabLle airborne sets operating in the frequency range of 0. 6 - 3. 0 GHz. 1

The Azimuth - Elevation Direction Finder will give bearings and signals from continuous wave (CW), amplitude modulated (AM), frequency modulated (FM), and pulse type RF transmissions. The Azimuth - Elevation Direction Finder is designed as a semi-fixed installation with an easily erected and disassembled antenna systemn which will permit a change of site with a minimum of delay. Accessory items furnished with the Direction Finder set aid in the proper orientation of the antenna system. Bearing information is obtained either from the visual digital readout provided with the electronic equipment. or from the teletype printout provided with the computer. 1.1.2 Components of the Azimuth - Elevation Direction Finder The following components make up the Azimuth - Elevation Direction Finder system: a) He ni.spherical Antenna System which consists of 17 circularly polarized spiral antennas designed to operate in the 0. 6 - 3.0 GHz range. b) Electromechanical Switch which interrogates each of the 17 antennas and properly provides the necessary interrupts to aid the computer in analyzing the data collected by the Azimuth - Elxvaition Direction Finder system. c) Receiver that operates in the 0. 6 - 3. 0 GHz frequency range. This piece of equipment is to be furnished by the user and is not incluldedl in the equipment supplied by the contractor (The University of Michigan, Radiation Laboratory). d) Video Amplifier (a component part of the Azimuth - Elevation analysis system). The purpose of this equipment is to amplify the video signals from the receiver to a level acceptable by the memory voltmeter. e) Memory Voltmeter - this instrument measures and records the peak signal that is present at each of the 17 antennas which in turn is fed to the multiplexer. 2

f) Multiplexer which takes the 17 outputs from the peak reading detector and sequentially transfers them into the computer for later analysis. g) Computer - makes the necessary analysis from the data ( l.llrcted from the 17 antennas and then determiines the azimuth and elevation direction of the incoming signal. h) Display System consists of the Nixie tubes which show the azillmutll and elevation data in a numerical form easily readable by an operator. i) Teletype - provides the operator with a means for communicating with the computer and can be programmed to readout additional information on the azimuth and elevation 1 I t iion and on other desired items of information stored in the computer. 1.2.0 Component Description Below is a short description of each of the major components of the Azimuth - Elevation Direction Finder. 1. 2.1 Description of Antenna System (Fig. 1) The antenna system consists of 17 cavity backed Archemedian spirals mounted on a 6 foot li; illl l.- lhlellispherical surface. Epllloying the coordinate system of Fig. 2 each antenna is mounted on the lelllisplherical surface as follows: one antenna is located at 0 = ' = 0. Eight anlt'wnlas are located at 0 = 40 and (equllly slpacled (at 45 increments) in 6. The remaining eight antennas are located at 0 = 800 and are equally spaced (at 450 incrlelents) in j. A longitudinal line has been inscribed on the surface of the lhemlisllphere and passes through the center of elements 1 and 9 of the antenna system. This longitudinal line is usually aligned to a cardinal point of the compass, north, east. south or west. Each of the 17 antennas are connected to the electrollechlanical switch through RG58/U (50 2) coaxial cable. The electrlolealll ical switch.ss lKc iated with the antenna system may be mounted in the room with the data 3

FIG. 1: Antenna System. 4

Zenith 0 0 =O = g90~ =O 90E 0 = 90~ 0 = 0 Nortn o 0 = 90 FIG. 2: Azimuth - Elevation Coordinate System. 5

analysis equipment. In the event the user wishes to reduce the losses in the system, the RG58 cable may be replaced with a low loss coaxial caiLl, such as the Andrew Corporation Heliax FH 1-50. The 17 circularly polarized antennas are 15 turn Archemedian cavity backed spiral elements. The cavity backed spiral is fed through a broadband (Duncan - Minerva) modified 1.,iltn configuration. The antenna base has four leveling screws, level bubbles, and a compass to aid in the positioning of the antenna system. 1. 2. 2 Description of the Electromechanical Switch The electromechanical switch is shown in Fig. 3. The,.'1,clr m,,lle11:lii.i11 switch assembly consists of the RF switch and the motor drive unit. The rotor of the switch is driven by a 1/8 horsepower synchronous speed motor through a multispeed gear tr 'I-. -i,, si stell. The multi-speed gear transmission provides the operator with a choice of ten rotor speeds ra.nging from 1 rpm to 1000 rpm. The motor is connected through a pulley and belt arrangement to the main drive system of the switch rotor. The RF switch is a frequency sensitive device designed to operate in the 0. 6 - 3. 0 GHz frequency range. Three outputs are obtained from the electromleclianical switch. One is the RF signal output which is fed to a receiver. The other two outputs are the data interrupt lines. One of the data interrupt lines provides a pulse output for each revolution of the rotor of the electromechanical switch. The second interrupt line provides a pulse output as each antenna is interrogated by the receiver. The two data interrupt lines are required to aid the computer in analyzing the data in the proper sequential manner. 6

FIG. 3: Electromechanical Switch and Drive Assembly. 7

1, 2. 3 T -\ntenna D.. Li Analysis System;' ig. 4) The antennra data;in alvsis system consists o>f the netccessa'ry elt.-cl tonic components to m-iake thel required calculations of the lredicted azimiuth and elevation direction of R1 F emissions in the 0. -. O G;Iz irecquency range. The;.ltali aiillysis systemn is not frequency', sensitive. however. it is senlsiti\cv to the pattern characteristics of the antenna system used. It is a )prreciLuisite that the electric field of the antenna system satisfy a cosine function. The 1.l.I. analysis system receives its inlput from a receiver equivalent to a MIicro Tel \VR-2~00 WVide 1Band Receiver. The signal -uttlp)t from the receiver is a voltage xwhose ampllitude varies proportionately with the signal input to thu receiver. 1. 2. 3.1 [wltt-Packard 450 Video Amplifier The video amplifier is a broadband high gain am plifier manufactured b1 the Heiwlett-P- ackard Company (Model 450A). The ampl:lifier is required to aml)lify the vidleo signals above the threshold le\-vel of the memory volhll l r. The broadi)and amplifier is employed to ensure that pulse signals will be faithfully a lmplified. A sw-itch on the front pan:el allows the selection of either '20dI or 40dB gain. A DC restoring network has 1- een ';d.lcl. d to the amplifier so that its output is al\ways positive. 1.'2.3. Micro InstLruments 5201-B-1 MIemorv Voltmeter The lmemlory -voltimeter (Peak- Detector) is used to detect the highest silgnal level available at each of the antenna elements as the aintenna switch interrogates thlc correspondingl switch position It is capal)le of registering,;all signals from DC to pulses as.hllrt as 50 nanoseconds. The voltmeter is ale tivax.ted by the compullllte at the samte time the antenna switch is coupling one of the antennas to the reciver- At the end of this period. the voltmeter output continues to record the lmagnitude of the largest signal present duringo the interval. 8

p urn M. i lI I. - ' FIG. 4: Data Conversion Equipment.

1. 2. 3. 3 Texas Instruments 848 Analog to Digital Converter The analog to digital converter (A/D) transforms the voltage output of the memory voltmeter into a digital form acceptable to the computer. On command from the computer, the converter samples the voltmeter output and forms the digital rllt'..eii'dLtati)n of it. This process takes about 29 psec after which the computer may read the result into its lllmemor-y. 1.2.3.4 Varian 620 I Computer The computer function is to control and coordinate the whole system It can turn the memory voltmeter on and off, trigger the A/D converter, read data from the A/D converter and display results (angles) on the NIXIE tube registers. Also, it has interrupt lines from the antenna switch and A/D converter which allow these devices to interrupt the normal operation of the computer to inform it that some external event has occurred. Available for use by the computer is a clock which can be turned on and off, and which interrupts at 100 usec intervals after being activated. Also; ' to the computer is a model 33ASR teletype through which the operator can communicate with the computer either by the use of the keyboard or punched paper tape. Likewise the computer can punch or print information for the operator. The core memory of the 620 I has 4096 words, each 16 bits long and a full cycle time of 1. 8 tsec. 1.2.3.5 Other Equipment In addition to the components described above, the main equipment rack houses logic circuitry which interfaces the computer with the various external devices and it also contains the 100 Usec clock. The NIXIE tube displays along with their high voltage power supply and some logic cards are mounted on the front panel. In back is a separate power supply used to run the logic circuits. 10

1. 2.4 Additional Equipment Required Thle following equipment although not supplied as a part of the Azimuth - Elevation Direction Finder set is needed for use with it. Power Source - The equipment requires a power source capable of supplying 115 volts - 60 cycle power at:I'plroximlIlttly 1000 watts. Standard commercial power is adequate and is not felt that additional filtering or regulation is required. Receiver - A second item required is a receiver. The receiver shlotld be capable of covering the frequency band of 0. 6 - 3.0 GHz. The sensitivity of this receiver slhouldc be at a mlinimlllum -70dBm. The receiver should provide a voltage output that has a linulc 40dB dynamic range as a function of the input. The Micro-Tel model XWR 200 receiver was used with this system. The Scientific Atlanta model 1630 wide range receiver should perform equally well. The entire sy>tt. in should be enclosed in a shelter to give adequate space for equipment and operator. A suggested shelter is a S-44/G. This -.1 li i, is a knock-do\wn type field imobile unit that may be used to house the l- i;liini personnel and equipment. For complete illllrlil,.ll') on shelter S-44/G, see TL11-2599. 1.3.0 System Application A single Azimuth - Elevation Direction Finder system is capable of determining the azimuth and elevation bearing of a distant transmitter. At present it alpearls that azimuth and elevation data are a'ccLurate to within + 5. Elevation data is reliable only when the source is located 300 or more above the horizon. However, azilmuthl data is accurate to within + 5 tllroughl the entire range (azimuth angles from = 00 - 360 and elevation angles from 0 = 10 - 90 ). For the purposes of this system a stand.l lld spherical coordinate s stemll (Fig. 2) is employed. 11

1.4.0 Data Interrupt Pulse Gellerator Associated with the Azimuth - Elevation Direction Finding system is a 17 element antenna array and meclhanical switch to scaln the array. It is necessary to alert the system when one particular antenna is switched into the circuit. This is accomplished by a series of holes in the switch rotor. A light source is placed on one side of the rotor and a light sensitive diode on the other. The holes are arranged so that when an antenna is switched into the receiver, the light passes through the hole and illuminates the photodiode. The diode is connected to a Sclhmitt trigger, which generates the necessary pulse to alert the com01puter that data is available. Figure 5 is a schematic diagram of the pulse generator circuit. The circuits for the 1 pulse per revolution and the 17 pulses per revolution chllannels are identical. Q1 is a current preamplifier and its function is to insure that a high impedance is maintained across the diode while providing a moderate impedance intput to the trigger circuit. Q2 and Q3 comprise the trigger circuit. The trigger has an input threshold of about 3 volts and a hysteresis of slightly over one volt. This provides a high degree of noise immunity and precludes any potentially unstbl.le illumination levels. The switch output controls Q4 which is an emitter follower current amplifier. Q4 is used to drive the cable connecting the switch locLation to the computer location. Cable lengths exceeding 100 feet of RG-58 have been -t.... 'iI,,y used The pulse is differentiated and received by Q5 which s\\ itches the computer interrupt line. The unit described has been in use for the past several months and has experienced the extreme \variati()ons of temperature and humidity associated with a MIichigan autumn w\ithout any sign of performance degradation. 12

D B 11 B1 To Pulse Receiver Q1 2N 2386 Q2' Q4 21 708 Q3, Q5 2 2270 D HP 5082-4203 D2, D8 6V Zener D3 1N457A D -D7 1N2071 4 7 D9 9V Zener B No. 44 Bulb T 12V CT 1A 1 Pulse Generator I-' (^0 To Lamps t t Q5 To Computer Interrupt From Pulse Generator Pulse Receiver Regulated Power Supply FIG. 5: Data Interrupt Pulse Generator

CHAPTER 2 INSTALLATION The accuracy of the Direction Finder (DF) depends to a great extent on its location. Factors that must be considered in selecting the site are the ground contour, obstructions that may be in the vicinity of the antenna system, the nearness of the antenna system to large bodies of water and its height above the ground. Therefore, it is important for the user to inspect the proposed site with the following i. li'lucti.inS in mind. 2. 1.0 Selection of Site The site area should be gently rolling within the first 150 to 200 yards from the center of the antenna array. Whether installed in rolling or mountainous country the antenna system should be located at the highest elevation. Efforts should be made to avoid large bodies of water when possible. Therefore, it is clesirable to locate the Azimuth - Elevation DF system inland if lpossiblc. If it is necessaly to locate the antenna system near the co,~:.l, it is suggested that the user select a flat site and install the antenlna as high as t,.:.il.i,1 above the surface of the water. Regardless of where the antenna system is located, it is important that it not be installed near tall trees, buildings, wire fences, power or telephone lines, radio antennas, chimney stacks, or other tall obstructions. 2.1.1 Preparation of Site It is sulggIrsted that the antenna system be placed on a tower 40 feet or more above the surface of the ground. It is recommended that the '.!!M:liin.th' of the DF equipment be located in a room directly li.-it;.li the antennia system so as to minimize the length of cables that interconnect the anrtenna system 14

with the electrcollechlanical s\\itclh assumed to be located inside the shelter. In the event commercial power is not available. a portable unit capable of supplying 115 volts and 1000 watts of 60 Hz power will be IL-CCSS. Il'y. It is suggested that the power unit be lucall.l. at the base of the tower for simplicity of operation. 2. 1. 2 GCln:ral Instructions The developer of the Azimuth - Elc:lt ioni DF system has not had extensive experience with the system and there is still much to be learned in regards to the accuracy of the system. During the initial tests of azimuth - elevation DF system, the user should concentrate his efforts at 1. 6 GHz, since this is a ft'requencyl at which the individual elements of the an1llttllla system operate reasonably well. As the user gains experience with the DF system and increases his kno, l,1o, of the flexibility of the computer in the procet,.sillg of data, it is felt that the accuracy of the system can be improved at other frequencies in the 0. 6 - 3.0 GHz frequency range. It is our belief that the accuracy of the system is strongly dependent upon the site, therefore much care must be taken in its selection. 2.1.3 Antenna TIstallaltioni The array of 17 antenna elements was delivered with the antennas installed in the hemispherical surface and cabled to the 17 output jacks located in the lower portion of the hemisphere. The hemisphere is bolted to the wooden platform through four mounting holes during shipment. Four leveling screws, four 8" x 8" Benelex base plates and 17 six-foot RG58/U cables are included with the antenna system. 15

Q

2 1 3. 9 In the event the user wishes to position the antenna to 'true' northl, he must refer to a map of the local area to determine the declination east or west of north and set this accordingly on the vernier scale (the long lines on the vernier scale are 1 illvI..!ni'-llL; the short lines are 1/10th degree increments). 2 2.0 Cabling of the Azimuth - Elevation Direction Finder 2.2.1 ILst:illlation of Power Cables The data link cable and the power cables for both the computer and the teletype are packaged inside the back of the teletype console. The back of the console is removed by removing the two phllips screws at the top of the console and sliding the panel out. 2. 2.1. 1 The data link between the teletype and computer is installed by tilting the computer forward and installing the plug into the receptacle (36) in the lower right-hand portion of the computer cabinet. 2. 2.1. 2 The AC cable of the teletype is installed in the AC plug mold at the back of the computer. The AC line to the computer can be plugged into any 115 volt single phase outlet. The power requirement for the computer teletype combination is 600 watts. The line voltage should be 115 volts + 10 volts with a line frequency of 60 Hz + 2 Hz. Operating temperatures for the Azi.iLutlL - Elevation Direction Finder are 00 to 450 centigrade inside the cabinet. 2. 2. 2 Antenna to Switch Cabling The anttellnna should be installed as in Section 2.1.3. 2.2.2. 1 Connect one of the 17 six foot RG58/U cab(lvll. from jack No. 1 on the hemisphere to jack No. 1 of the electromechanical switch. 17

2. 2. 2. 2 Continue with the remaining 16 six foot lengths of cable coiinlctinlg the anlltclnas in numerical order from 2 through 17 to the respective switch jacks that are numbered from 2 through 17. 2.2.2.3 Plug the s\vitch power cord to a single phase 115 volt, 10 amp, 60 Hz circuit. Operating temperature of the switch is 100 to 400 centigrade. The switch is not weather-proof and should be kept in the equipment shelter as noted in 2. 1. 1 to prevent damage to the precision machined (uace:ls. The speed of the switch is controlled by the knurled aluminum knob on the (green) Geartronics gear box. (NOTE: Change speed only with the motor off). Speed position No. 1 results in a 1000 rpm operation of the switch. Position No. 2 of the switch is equivalent to a 2:1 gear reduction resulting in 500 rpm operation of the switch; other positions of the switch are similar indications of the gear reduction. 2. 2. 2. 4 Turn on the AC switch and note that the output shaft of the Geartronics gear box is turning. In the event the output shaft does not turn, it will be necessary to turn the motor off and jiggle the speed switch while the motor shaft is hand rotated until gear meshing is felt, then turn the AC sxwitch on. 2. 2. 3 Computer to Switch Cabling Connect the two lengths of RG/58 cable labeled Nos. S-1 and S-17 to the two BNC termlinations (S-1 and S-17) on the switch pulse generator located on the electrcoit. li.,, i1 switch to the two BNC terminations (S-1 and S-17) on the data interrupt ]llmodule inside the back of the computer. 2. 2.4 Cabling the Receiver It is recommended that a Micro-Tel receiver or its equivalent be used with the Azimuth - Elevation DF system since the system is designed to operate 18

employing a linear voltage -It i Ic i-" similar to that available from the MicroTel receiver. 2.2.4. 1 Cable the electromechanical switch using the center RF connector of the stator of the switch to the receiver input employing the cable labeled "RF" (RG9/U cable, approximately 8t long). 2.2.4. 2 The video output of the receiver is connected to the input of the video amplifier located in the computer rack using the cable labeled "Video" (RG58/U cable, approximately 3' long). It is to be noted that an APR-4 receiver may be used with the system. However, when using this receiver, it is important the AGC circuit be turned off or disabled. In this case the video output is again connected to the input of the broadband amplifier located in the computer cabinet as noted above. 2.2.5 Cabling the Broadband Amplifier to the AIemoLry Voltmeter The signal from the amplifier may be monitored by the tee installed between the amplifier and the memory voltmeter by connecting a cable from the tee to one input of a dual trace scope. The dual trace presentation may be stabilized by connecting a cable to a second tee installed on the input side of the data interrupt module (connection S-1 located in the back of the comllputer) and connecting this cable to the second input of the dual trace scope. By synchronizing the display to the single pulse per revolution the individual voltage from the switch can be stalilizel, and become more meaningful, since it is possible to observe the data being collected from each anltelnnia sequentially from 1 through 17. The output of the receiver should be adjusted until the display from the broadband amplifier has a maximum of 10 volts as 19

noted on the oscill>'-c'),lt.. This is iimportant since the memory voltmeter cannot detect voltages greater than 10 volts and excessive voltages will introduce errors into the DF svstem. With the computer turned on print out "A" table (see pa iagrlapl 3. 1. 3) and observe if all values are less than 2047. In the event one or more has a value of 2047 reduce the receiver gain until all values are less than 2047. The scope may or may not be used at the (liscretion of the user. No further cabling is required as the memory voltmeter is connected internally to the A/D converter which in turn is internally connected to the computer. 2. 3.0 Tutrn-on Procedure for Azimuth - Elevation Direction Finder System IMPORTANT IT IS IMPERATIVE THAT THE TURN-ON PROCEDURE DESCRIBED BELOW BE FOLLOWED EXACTLY SO AS TO PREVENT DAMAGE TO THE COMPUTER PROGRAM. IF THESE INSTRUCTIONS ARE NOT FOLLOWED; THE COMPUTER PROGRAM MAY BE DAMAGED AND THE PROGRAM WILL HAVE TO BE RE-INSERTED INTO THE COMPUTER. -- IMPORTANT 2.3.1 Computer Turn-On The computer turn-on must be followed in the following step-by-step sequence. 2. 3. 1.1 Turn on computer and rack power by pushing the 'on' button located on the right side of the computer. 2. 3. 1. 2 T''i, on the teletype with the switch located in the right hand corner of the teletype; rotate switch CCW to 'line'. 2. 3. 1. 3 Place the tole,, switch labeled 'memory' (in the upper right hand corder of the computer) to 'enable'. 20

2.3.1.4 The register 'U' should be p)laced in an 'up' position with all other register switches 'down'. 2.3.1.5 Depress the 'reset' switch of the upper row of 20 switches. 2.3.1.6 Place register 'P' up with all other registers down. 2.3.1.7 Again depress the 'reset' switch. 2.3.1.8 Depress the 'system reset' switch. At this time all lights on the face of the computer should have been turned off except for the light titled 'step' which should now be on. 2.3.1.9 On the front of the computer you will observe five groups of three switches in a group. Depress the red switch of group 3 and a light will occur. 2. 3.1.10 Now depress the 'run' switch. If the computer is operating properly, the 'step' light will turn off and the 'run' light will turn on. IMPORTANT - IF THE RUN LIGHT DOES NOT OCCUR AND THE COMPUTER STILL INDICATES 'STEP' DO NOT PUSH THE 'RUN' SWITCH AGAIN, AS THIS WILL MODIFY THE COMPUTER PROGRAM. IF THE COMPUTER DOES NOT DISPLAY A RUN LIGHT, PLACE THE 'MEMORY' SWITCH TO ' DISABLE' AND REPEAT STEPS 2.3.1.3 THROUGH 2.3.1.10. IF YOU DO NOT OBTAIN A RUN ON TWO CONSECUTIVE TRIES, CONSULT A COMPUTER PROGRAMMER. IMPORTANT. 2.3.1. 11 If a run light is lit the sense switch S-1 should be in the 'up' position. S-2 and S-3 shoIuld be placed in the 'down' position. The computer is now ready to operate the Direction Finder system. 2.3. 1. 12 Turn on electromechanical switch. 21

To prevent erroneous readings, the Azimuth and Elevation display is not turned on (display tubes do not turn on) until a signal of a pre-set magnitude is read into the computer. This is accolmplislled automatically and does not require any command from the operator. This prevents the computer from displaying erroneous answers which are due only to the noise level in the receiver and amplified by the broadband alllplifier. This level can be adjusted by the teletype console and is to be made only by a compulc' programmer. and is discussed in paragraplhs 3. 1. 3 and 4. 2. 0. 2. 3. 2 Turn-Off Procedure for the Azimuth - Elevation DF System To turn the computer off there are several simple steps that must be observed to prevent damage to the computer program and are as follows. 2. 3.2. 1 Depress key 'H' on the teletype keyboard. IMPO()RTANT i IF KEY 'H' IS NOT DEPRESSED BEFORE TURNING THE COMPUTER OFF, THE CURRENT INSTRUCTION MAY BE LOST FROM MEMORY AND THE PROGRAM MODIFIED SO THAT THE COMPUTER WILL NOT OPERATE UNTIL RE-PROGRAMMED. IMPORTANT 2. 3. 2. 2 Switch the 'memory' toggle switch on the front of the computer to '(.isablle'. 2.3. 2. 3 Turn the teletypewritter off. 2. 3. 2. 4 Turn the computer and the entire rack off by depressing the 'on-off' switch on the front of the computer. 2. 3. 2. 5 Turn off the electromechanical switch. 22

2. 4. 0 Computer Program Modification High voltage pulses from -lc(c-trnlic equipment such as a radar can modify the computer lp'og'at.ll. For this reason, the Azimuth - Elevation Direction Finder should not be operated in the proximity of such equipment. If the computer program is modified by voltage pulses or operator error, a computer.piograllIner must be colsllltt.Ud. The computer programmer can read the program tape (see Chapter IV for a discussion of tapes) into the computer according to the instructions in the Program Reference Mianual (page 3-4) under the heading "Binary Load/Dump". NOTE: This is not to be done by an operator. The instruction counter on the computer face is in octal with 3 bits per octal number. In each group of three on the instruction counter the value of the right tab is one, the center tab is two and the left -:iJ has a value of four. If complete allcitrtion of the computer memory has occurred, the computer lOug rammer will have to use the boot strap loader tape (see Chapter IV) shipped with the computer. Instructions for the boot strap loader )l),tLogra are found in Section 3 of the Programming Reference Manual (Manual IX). 23

CHAPTER 3 COMPUTER INSTRUCTIONS AND TABLES 3.1.0 Teletype Keyboard and Command Through the use of the teletype kleyboard, operating personnel are able to *i.,,,iiil',iti with the computer within the limitations of the program that has been inserted into the computer. The program employed with the Azimuth - Elevation Direction Finder has been written to provide a maximum degree of flexibility. To increase the degree of flexibility. the program is written with six fixed instructions (that cannot be changed by the operator and are a part of the computer program) and nine v: irk1l)1 instructions (that may be implemented throughL the use of the keyboard by the operator) in addition to ten auxiliary instructions (which are required when personnel wish to converse with the eight tables that are used in the Azimuth - Elevation Direction Finder program). 3.1.1 Fixed Instructions The six fixed instructions associated with the Azimuth - Elevation Direction Finder are listed in Table I. All data for these instructions are in numerical form employing a base 10 system. TABLE I FIXED INSTRUCTIONS Key Instructions 1. Depress Key C Calculate antenna coefficients from P and T tables and S value. 2. Depress Key D Disables interrupts. 3. Depress Key E Enables interrupts. 4. Depress Key G T-type will print out Hi, Lo, and Avg of ten scans of computer. 5. Depress Key H A stop command is given to the computer. 6. Depress Key V T-type will print out current azimuth and elevation position. 24

Key 'C' - Whenever the 0 and 0 angular positions associated with cacli of the 17 antennas are reassigned, a change in the 'TT (0) and I'P (I) tables is required. However, before the correct data can be displayed by the NIXIE tubes. the operator must depress key IC' of the teletype to ensure that the proper antenna coefficients have been calculated for the new 0 and 0 pointing vectors, and inserted in the x, y, and z tables. Keys 'D' and 'E' - Keys 'D' and 'E' are self cxsl)lalnitoory in that they either disable or enable the inteIrrupts from the electromechanical switch. Key 'G' - Activation of key 'G' is essentially asking the computer to read out the average of ten computer scantls of Azimuth and Elevation data, and also to print the high and low value that was noted during those ten scans. Key 'H' - Key 'H' is employed to stop the operation of the computer as is noted in the turning-off procedure in paragrapll 2.3.2. In the event 'H' is inadvertently depressed during normal operation, the operator must restart the computer by following the procedures of 2. 3.1.4-2. 3. 1. 10. Key 'V' - 'V' is used when the operator is interested in having the C(. I'l'.il Azimuth and Elevation data printed out on the teletype. 3. 1. 2 Variable Instructionls The second form of instructions are variable instructions. There are nine vairiable instructions available to operating personnel and are listed in Table II. TABLE II VARIABLE INSTRUCTIONS Key Instructions 1 F Weighting factor associated with the B table. 2 I Automatic cycle length. 3 J Low signal level cut off. 4 K Low antenna level cutoff. 5 L Memory voltmeter on time. 6 M Display change interval. 7 N Num1t:be of antenna elements. 8 Q Display hold time. 9 S 0 and 0 scale filacltr. 25

To make a change in the variable instruction, the operator must first depress the numerical change he wishes to make and then depress the key of the part i (Cu La' variable instruction he wishes changed. For example, in the event the average \uitillnm factor 'F' is to be changed from its present value of 10 to 20, the operator would type '20F'. In the event the operator is interested in learning what variable ilst rulllion is presently inserted in the computer, he merely needs to depress the key of the instruction he is interested in and the teletype will print out the present ilstl'ruction that is in the computer. Key 'F' - The 'F' key as noted in the table is the averaging factor that is associated with the B table as noted in the following expression. (F-l)B + A n-1 n B = n F where n = scans in time A = new value from A/D converter n B = previous value in the B table. n-1 Key 'I' - Key 'I' is discussed in paragraph 4. 2.6 and not used by the operator. It should be set to 'zero' for normal operation. Keys 'J' and 'Q' - Keys 'J' and 'Q' sets the minimum acceptable level at which a minimum usable signal is considered to be present. If all antenna element levels are less than the 'J' value no calculations are made for this scan and the NIXIE tube display is not changed. Furthermore, if this condition exists for more than 'Q' successive scans, the NIXIE tube display is turned off. The 'J' value should be limited to a range of 0 - 2047 which corresponds to a voltage range of 0 - 10 v at the input of the memory voltmeter. A suggested value for Q is 4000. 26

Key 'K' - It is possible to limit the data employed by the Azimuth and Elevation prediction such that only data from the stronger portions of the a;ltnnlll;L radliation patterns are used. This is:accomlllished by coml)uting a cutoff level which is a fraction of the maximum signal present for a particular scan. If a level on any particular antenna is less than the cutoff value that antenna is set to zero. The fraction used to set the cutoff level is K/1000. In the event data for all antennas are to be used K should be set to zero. Key 'L' - Key 'L' is associated with the on-time of the memory voltmeter in units of 100 iusec. Thus typing '1 L'forces the voltmeter on time to be 1000 psec. It is important to note that when 'L' is set to zero the ontime is determined automatically by the computer which is considered to the "normal" mode of operation. Key 'M' - Key 'M' delt tlnii!t - the display change interval. This interval may arbitrarily be set by the operator. A typical interval is 20 which tells the computer to change the NIXIE tube display to current value after each 20 computer scans of the data. Key 'N' - 'N' represents the number of antenna elements used in the system. Presently tliarte are 17 elements in the s.ste l. Key 'S' - The purpose of 'S' is to provide the i,)p It'llr with the capability of entering fractional parts of a degree. The 'T' and 'P' entries are divided by 'S' when they are used by the colmputer. 3.1.3 Computer Tables The eight tables associated with the Azimuth - Elevation system are listed in Table III. 27

TABLE III Computer Data Tables 1 A Input data from electromechanical switch. 2 B Input data from electromechanical switch as modified by 'J', 'K' and 'F' instructions. 3 P 0 position assigned to each of the antennas. 4 T 0 position assigned to each of the antennas. 5 W Weighting factors for elevation data, to be changed only by a computer programmer, (see lal'ragir:lli 4. 3. 1). 6 X X coefficients. 7 Y Y coefficients. 8 Z Z coefficients. Keys tA' and 'B' - The 'A' and 'B' tables are essentially data that is generated as a result of the input data directly from the electromechanical switch. The 'B' table differs from the 'A' table in that it is modified by the 'J', 'K' and 'F' instructions. The numlers in these tables range from 0 - 2047 which correspond to a voltage range of 0 - 10 V at the input of the memory \,1t,'ecter. Keys 'X', 'Y', and 'Z' - These tables are the x, y, and z coefficients which are calculated from the 'P' and IT' tables when key 'C' is depressed. Keys 'P' and 'T' - The 'P' and 'T' tables contain respectively the 0 and 0 positions assigned to each of the 17 antennas. Values to be entered in the 'P' and 'T' tables are obtained by lmultiplying the 0 and 0 antenna positions in degrees by S (see Table II for a description of S). As was noted previously, the mere insertion of data in the 'P' and 'T' tables will not cause the computer to display the proper azimuth and elevation coordinates of the iii( "1flin signal on the NIXIE tubes unless the instruction key 'C' of Table I has been depressed. 28

3.1.4 Auxiliary Instructions Table IV is a list of the auxiliary instructions that are used when co:'ll,!'!iili;i.;l!, with the computer. TABLE IV AllNi i;ary Instructions Key Instructions 1 1 - 0 Accumulate current input number 2 - Change sign of current input number 3 = Print current input number 4 <- Delete current input number 5 E SC Stop printing and clear input )buffer 6 CTRL-A Simulate switch interrupt 7 CTRL-Z Simulate zeroing switch interrupt 8 RETURN Carriage Return, line feed, delete current number 9? Print Current Table 10, Set/Print Current Element nutmber 11 / Set/Print Current table entry Numbered Keys - The digits in the current input number are entered by employing the number keys in the normal typewriter manner. The maximum magnitude of the current input number is 32767. Minus -' Sign Key - A '-' sign indicates a change in the sign of the current number being inserted. Equal '=' Key - The '= signature causes the computer to print out the current input inumber. 'I-' Key - The '<-' key deletes the current input number. Escape 'ESC' Key - In the event it is desired to stop the output from the computer, the 'ESC' key may be depressed. This will stop the printer and clear the input buffer. 29

Control 'CTRL' Key - It may be necessary for a progranmmer at times to silmulate switch interrupts. This may be done by depression of the 'CTRL' 'A' keys or if he wislles to -ilhnll:lti zeroing switch interrupt this can be done by depression of 'CTRL' 'Z'. RETURN Key - Returns print head to left side of page spaces the paper and deletes the current input number. To comnIuil1nicatelt' with the tables of the computer there are three coinmands in add.litioll to the t:il,l letters of Table IV that must be used. These colmmanscl are the question mark '?', comma ', ' and the slash '/' Whenever a table letter is typed that table is established as the 'current table' and remains as such until another table letter is typed. '?' Key - To print the entire content of the 'current table' one must enter the appropriate table letter followed by a question mark, e. g., 'A?' will cause the A table to be printed out. Two aclditional terms rassociated with the computer table..s to be defined here are the 'table entries' and the 'table indexes'. Each of the computer tables contain 'table entries' which are the numbered values in that table. The 'table index' is a number between 1 and N which specifies a particular 'table entry'. ',' Key - The 'table index' is set by typing the desired table letter and index number followed by a comma ',', e. g., '1' will set the table index to 1. To read out the present index value type a comma, e. g., '' will print out the curtrent table index number. '/' Key - The 'table entry' in the 'current table' which is specified by the 'ta:ll) index' is printed or changed by use of the slash '/'. A value may be entered in this entry by typing the desired table letter, index number, comma, and entry value followed by a slash '/', e. g., 'A2, 21/' requests that the value 21 be inserted in the second entry of table A. This operation also increments 30

the table index after the value is stored. To print out the present 'table entry' enter the table letter, index number, a comma followed by a slash '/t, e. g., 'B4, /' requests that the value of the fourth index of talble B be printed out. This number is then esta:llislled as the current input number. 3.1.5 Preliminary Checkout of System With the system turned on in:ccordanll C with paragraplh 2. 3.1, the following procedure may be followed to check out system operation. 3.1.5. 1 Disable computer interrupts by depressing Key 'D' on the teletype. 3.1. 5. 2 Print out 'P' table by depressing Keys 'P' and '?' of the teletype. 3. 1.5. 3 Print out 'T' table by depressing Keys 'T' and '?' of the teletype. NOTE: The 'P' and 'T' values printed out are respectively the azimuth and elevation coorcldinates associated with each of the 17 antennas and are printed sequentially as follows: P 1 P2, P3.......P 17 and T1 T T.... T 17' 3. 1. 5. 4 Enter the following 17 numbers in the A table as follows: Al, 1000/0/0/0/0/0/0/0/0/0//0/00/0/0/0/0/ 3. 1. 5. 5 Observe the Nixie Tube display to see that the elevation data agree with T and that the azimuth data agree with P1. 3.1.5.6 In the event an error is noted in 3. 1. 5. 5 there is trouble in the computer program and a computer programmer must be consulted. 3. 1.5.7 If there is no error in the data of 3.1.5. 5 the computer is operating properly. 3. 1.5. 8 Enable computer interrupts by depressing Key 'E' of the teletype. 3. 1. 5.9 Disconnect the cable from the input to the memory voltmeter. 3. 1.5. 10 Disconnect the l I l 1,,. t l,.ll i;l switch output cable from the receiver input. 31

3. 1. 5. 11 Connect the output of the electromechanical switch to the input of the memory voltmeter. (The switch may be running during this step). Note: a connector adapter may be required to make this connection. 3. 1.5. 12 Disconnect the 17 cables (from the antenna system) from the 17 inputs of the electromechanical switch. 3. 1. 5. 13 Connect a 5 volt DC or video source to input port 1 of the electromechanical switch. Note: The meter and front panel control knobs of the memory voltmeter l)erform no useful function in the azimuth and elevation direction finder system. However, it is recommended the range selector switch be placed in the 10 volt position. 3.1. 5. 14 Observe the azimuth and elevation Nixie tube displays. Print out the current azimuth and elevation values by depressing key 'V' on the teletype. One should observe that these two sets of data agree and they both should be equal to P1 and T1 of 3.1. 5. 3. 3. 1. 5. 15 In the event 3. 1. 5. 14 is in error print out the A table by depressing (A?) on the teletype keyboard. One should observe a number in the range of 1000 + 100 in the first position of the A table and very large negative numbers in the remaining 16 positions. 3. 1.5. 16 In the event 3. 1. 5. 15 is in error trouble exists in either the memory voltmeter or A/D converter and a competent electronic repairman or coj)L pulter programmer should be consulted. 3. 1. 5. 17 If 3. 1. 5. 15 is satisfactory disconnect the output of the electromlltCi iNal switch from the memory voltmeter and reconnect the output from video amplifier to the memory voltmeter input. 3.1. 5. 18 Turn off the DC or video source. 3.1.5.19 Disconnect the output of the RF receiver from the input of the video amplifier. 32

3. 1. 5. 20 Place the gain switch of the video Iamllplifier in the 20dB position. 3. 1. 5. 21 Connect the output of the electrolmlecllhanical switch to the input of the video amplifier. 3. 1. 5. 22 Turn on the DC or video source and adjust. the output for a 0. 5 volt signal. 3.1.5.23 Repeat 3.1.5.14and 3.1.5.15. 3.1. 5. 24 In the event 3.1. 5.15 is in error trouble exists in the video amplifier and a competent electronic repairlan should be consulted. 3. 1. 5. 25 If 3. 1. 5. 15 is satisfactory disconnect the output of the electromechanical switch from the video amplifier and reconnect the receiver output to the video amplifier input. 3. 1. 5. 26 Disconnect the DC or video source from input No. 1 of the electromlnechanical switch and connect a RF signal generator having a frequency in the range of 600 MHz to 3. 0 GHz and a calibrated output to input No. 1 of the electromechanical switch. 3. 1. 5. 27 Connect the output of the electromechanical switch to the input of the receiver. Check to be sure the receiver is turned on and tuned to the frequency of the RF source. 3. 1. 5. 28 Adjust the RF source to produce a CW output and adjust the level to -45dBm. Set the receiver gain to mid-scale. 3. 1. 5. 29 Print out the A table of the computer by depressing (A?). 3. 1. 5. 30 To comply with the remainder of this step it will be necessary to repeatable print out the A table as noted above. A number should occur between 0 and 2047 only in the first position and large negative numbers in the remaining 16 positions. In the event 2047 occurs in the first position reduce either the signal generator level or the receiver gain until a number between 1000 and 2047 can be obtained. In the event 0 or a negaltive number occurs increase either the output level of the signal generator or the receiver gain until a number between 1000 and 2047 can be obtained. 33

3. 1. 5. 31 In the event numbers g,.-tt t' than 0 occur in more than one position of the A table in the above step or the conditions of 3. 1. 5. 30 cannot be complied with trouble exists with the receiver and a competent electronic repairman should be consulted. 3. 1. 5. 32 If 3. 1. 5. 30 is satisfactory print out the current azimuth and elevation data by depressing Key TV' of the teletype and observe the Nixie tube display. This data should agree and also should agree with the data for P1 and T1 of step 3. 1. 5. 3. In the event it does not a competent computer programmer should be contacted. 3. 1. 5. 33 Disconnect the signal generator from input No. 1 of the electromechanical switch and reconnect the 17 antennas to their respective switch positions. 3. 1. 5. 34 To check out the antenna system it is recommended that the antenna system be placed on an antenna range and a RF CW signal at a frequency of 1. 6 GHz be radiated from a known azimuth and elevation and the signal processed by the A-EDF system. If the NIXIE tube display designates 50 the azimuth and elevation of the signal accurately to within + 5, the antenna system is operating properly. 3.1. 5.35 In the event an error exists in 3.1. 5.34 one or more of the antennas may be faulty and an antenna specialist should be consulted. 3. 1. 5. 36 Turn off the equipment in accordance with plarag rallph 2. 3. 2. NOTE: During the operation of the system, the operator will observe that the light on the front of the A/D converter flickers. He should not be alarmed as this is normal for the A/D converter. 34

CHAPTER 4 COMPUTER PROGRAM 4.1.0 Introd(uc tion The following is a detailed description of the computer program for the Varian 620/i used by the Azimutlh - Elevation Direction Finder system. It is assumed that the reader of this section is familiar with general programming notation and terminology and with the specific traits of the 620/i. The material in this section along with information given in the various 620/i computer manuals should allow the programmer to modify or extend the direction finder program as desired. 4. 2.0 General Program Operation This program makes use of the interrupt system available on the 620/i to communicate with the external devices connected to the computer. These devices include the fu'll owing: 1) the antenna switch which interrupts on interrupt line 2 once for each antenna and on line 3 once for each revolution of the switch. 2) the 100lsec clock which interrupts on line 1, 3) the A/D converter which interrupts on line 4 when it is through converting. 4) the teletype which uses line 5 when it finishes typing a character and line 6 when a key is struck or the tape reader reads a character. Associated with each of these interrupt lines is an interrupt location and an interrupt processing routine where action appropriate to each interrupt is taken. The main loop of the program looks at the data from the antennas which has been read in by the interrupt time i.iC it, l and from this deter minies 35

the azimuth and elevation of the incoming signal. This is accomplished by reducing the signal from each antenna element into X, Y, and Z components. The corresponding X, Y, and Z components from the 17 antennas are added and the result is expressed in terms of a spherical coordinate system. Because the antenna elements are located only on a hemisphere instead of on a full sphere, a correction must be applied to the elevation result as obtained above. The correction is made by using a piecewise linear approximation, the breakpoints and slopes for which are stored in the W table (WTAB) which may be changed from the teletype. The program inspects the antenna data to see that at least one element has a signal level greater than a minimum specified by cotntrol code 'J', and if not, then the entire set of data is skipped. If the level on any one element is less than some fraction of the maximum element level, as specified by control code 'K', then the level on that one element is set to zero. The value entered with (- 1ni i 1 code 'IM' determines how often the az i muth and elevation displays are changed while the code 'Q' determines the length of time the displays remain lighted after the signal goes below the level given with the 'J' control code. A large segment of the program is concerned with the processing of characters typed in from the teletype. This picks up characters from a buffer where they have been put by the interrupt processor, determines the meaning of each, and takes appropriate action No more than one character is examined between.- cans of the anute'L data and the time spent waiting for the teletype to finish typing out a character is spent scanningii the data. Note 36

that the teletype finished interrupt is not used, but rather a SEN instruction in the teletype output routine decides whether the teletype is still busy. The floating point numbers used in parts of the program are not the standard Varian form because of the limited use for them does not warrent the size and generality of the Varian supplied routines. E:ich floating point number used in this program conlsists of three computer words. The first word is the mlagnitude of the fraction part which is normalized with the radix point at the left hand end. The second word is the exponent part which is the negative of the integer power of two to be applied to the fraction. That is, if the second word contains a -4, then the magnitude of the floating point number is the fraction part times two to the power four. The third word is the sign and only the sign bit of the word is used. 4. 2.1 Program Description The detailed description of the programl is given with each part in order as it appears in the assenmbly listings. It may be of value to refer to the listing of each part as it is described. There are actually two separate assemlblics involved in the entire plt'ogram tl. This was necessary due to the restriction on the size of the symbol table available in the assembler. The first assembly is designated 'DF 1. 6', and c nll (,inis code for the interrupt processors and for the antenna data scan, while the second assembly is designated 'DF 2. 6', and contains code for the processing of control information from the teletype. The two assemblies are linked after they are loaded, eacLh time the program is started by a routine at the beginning of DF 2. 6 using a table in DF 1. 6. 37

ALLOCATION OF CORE SPACE Core Location (octal) Contents 0000-0017 0020-0037 0040-0107 0110-0117 0120-0177 0200-0227 0230-0645 0646-1067 1070-2017 2020-2416 2417-2777 3000-3030:-0:'; 1-3506 3507-4213 4214-5777 6000-7777 Interrupt locations DF 1 6 pointers DF 1 6 literals DF 2. 6 1)oinlters DF 2.6 literals Start location and linkage tables Data and temporary storage InterrLu)t processing routines Subroutines used il;ainl)' by DF 1. 6 Initiali/iationl and antenna data 1)l'(.c.'tL' ill g Unused Link routine General teletype processors and table Processors for specific characters Unused Varian debug routine, loader, etc. 4.2.2 Interrupt Locations DF 1.6 There are two core locations associated with each interrupt line; locations 0 and 1 for line 1, 2 and 3 for line 2, 4 and 5 for line 3, and so on. When an interrupt condition exists, the inst.ti'Lti-i,1 at the first of the 38

two locations is executed and if this is a double word instruction, the secondi.. is used also. In the parti.clclal case where the instruction is a 'JMPM', further interrupts are inhibited, but not forgotten, until the interrupt module is re-enabled by the program. Thus each interrupt processor must execute an 'EXC 0240' to turn the module back on. There is also an interrupt mask in the interrulpt module which allows interrupts on any line or set of lines to be selectively ignored. Note that there are eight interrupt lines a\vailable but only six are used. The other two may be implemented for other uses if desired. If more than one interrupt is pending at a time, the one with the lower line nunmber is taken first. 4.2.3 Teletype Interrupt Processor If the teletype key is hit, the interrupt is processed by the routine, TTYH. If the teletype key was a CTRL-A, CTRL-Z, or ESC, then immediate action is taken. A CTRL-A simlulates an antenna switch interrupt while CTRL-Z simulates a zeroing switch interrupt (which normally occurs once each rt'c'\-( t1(iill). In either case, the corresponding interrupt processor is entered. E SC clears the teletype input buffer and stops any printing that may be going on. If sense switch 3 is on, all other teletype characters are ignored. Otherwise, the character is stored in a buffer for later processing. The luiffeiL is circular and holds 20 characters so that if more than this nunmber is entered, before they can be processed, then later ones will rleplace earlier ones. 39

4.2.4 Clock Interrupt Processor During the time when the clock is on, it interrupts once at the end of each 100 usec. interval measured from the time it was turned on. During the period when the peak detector (memory voltmeter) is on, i.e., signals from the switch are being looked at, clock interrupts are directed to the processor "CLOK". At each interrupt, a counter (CCTR) is incremented and compared with a fixed number (NCS). If the counter is less than the limit, nothing more is done and the interrupted program is resumed. When the counter reaches the limit, the peak detecdr is turned off by executing 'EXC PDF', the A/D converter is turned on by executing 'EXC ADN', and location 1 is changed so that future clock interrupts go to the 'AUTT' auto-cycle processor. 4. 2. 5 Antenna Switch Interrupt Processor Each time the s\ itch moves into position so that the peak detector should be turned on to look at one of the elements, the switch interrupts to this processoir. The peak detector is turned on with a 'EXC PDN'. The processor then determines how long the peak detector is to be left on in the following manner. If there is a nion-zero value in the location NCS+1 (as stored there by the use of the IL' control code) then that value is placed in NCS. If NCS+-1 is zero, then the number in CCTR, which represents the total time since the last switch interrupt occurred, is divided by three and stored in NCS. In this automatic mode, the peak detector will always be on for one third of the time between switch interrupts. The clock is then turned on, and future clock interrupts are dire directed to the presso 'CLOK by changing the address in location 1. 40

4.2.6 Clock Interrupt Processor - Automatic Cycle During the time when the clock is running but the peak detector is off, clock interrupts are handled by the routine 'AUTT'. Each time an interrupt occurs, CCTR is incremented and compared with the value in AUTC which may be set by the use of the 'I' control code. If AUTC is greater than zero and if CCTR is greater than or equal to AUTC, then a fake switch interrupt is generated. This automatic cycling is sometimes useful in debugging the program when no real interrupts from the switch are;:\ailabll. If AUTC is zero, no automatic cycling takes place and if also NCS+1 is non-zero, indicating a fixed peak detector on-time, then the clock is turned off since it is not needed. 4.2.7 Analog/Digital Converter Interrupt Processor The A/D Converter interrupts each time it has finished converting a number, or about 29 /sec after it is signaled to begin conversion. When the iIntel'rrult occurs, the processor reads the digital result and stores it in the A table (ATAB). The location APTR contains the address in ATAB into which the current antenna value is to be stored. The processor increments APTR and if it then points above the top of the table, resets it to the start of ATAB. 4.2.8 Zeroing Switch Interrupt Processor Once each revolution of the antenna switch this interrupt is given for the purpose of positively synchronizing the position of the switch with the pointer, APTR, in ATAB. When the interrupt occurs, APTR is set to the bc', ii I., of the input table, ATAB. 4.2.9 BNBC: Binary to BCD Conversion This routine is called with a binary number in the A regi st -i and tretuIlr.I the BCD equivalent in the A and B registers. The low order four 41

decimal digits of four bits eaci are in the B register while the high order digit is in the A register. The number is assumed to be positive. 4. 2. 10 Teletype Output Routines The routines TCW and TCAW are used only during initialization to set up the teletype, and at no other time. If the teletype is busy, they enter a loop and wait for it to finish. 4. 2.11 FATN: Floating Point Arctangent This subroutine computes the arctangent in degrees between 0 and 360 of X/Y where X and Y are the two floating point arguments whose addresses are given in the calling sequence. The program computes either X/Y or Y/X whichever results in a magnitude between zero and one and uses the Varian routine, XATN, to actually compute the inverse tangent. The correct quadrant for the result is determined from the signs of X and Y and the integer answer is returned in the A register. 4. 2.12 FSQT: Floating Point Square Root FSQT computes the floating point square root of the floating point number whose address is given in the calling sequence. The result is stored back in the location of the argument. The sign word is ignored and unchanged. The Varian routine, XSQT, is used to take the square root. 4.2.13 FNMZ: Floating Point Normalization This routine is entered with a double precision fraction in the A and B reg i l t. and exponent in the X register. It returns with the fraction normalized in the A and B registers and the exponent adjusted accordingly. Note that if the fraction is all zeros, then the X register is made to be the largest possible positive number which corresponds to the smallest pI,.j'> ilf) 1c exponent. 42

4.2.14 FMPY: Floating Point Multiply FMPY computes the product of two floating point numbers whose add(h'css.,cs are given in the call. The result is returned with the exponent in the A register and the fraction in the B register and no sign given since the signs of the operands are ignored. 4. 2.15 XDCO: Double Precision Complement This is a Varian supplied routine which takes the 2's complement of the double precision number in the A and B registers and leaves it in the A and B registers. 4. 2. 16 FADD: Floating Point Addition The:I!l:Lliitll' of the two floating point arguments whose addresses are contained in the calling sequence are added together and the result returned with the!,'.I i,..1 in the A register and the exponent in the B register. 4. 2.17 XSQT: Fixed Point Square Root This Varian routine takes the square root of the number in the A register and returns it in the A register. If the number is negative, the error exit in the call is used. 4.2.18 XATN: Fixed Point Alrctangclllt This Varian supplied routine takes the arctangent of the number in the A register, which must be between zero and one in magnitude and returns the result in radians in the A register. 4.2.19 POLY: Polynomial Evaluator This routine is used by several of the Varian functions to evaluate the polynomials used to compute the sine, cosine, arctani, etc. See the Varian manuals for details. 43

4. 2. 20 XDAB, XFLT: Integer to Floating Point Conversion These two subroutines are used to convert a double precision integer into a floating point equivalent. XDAB takes the absolute value of the integer whose address is given in the call and stores it back in that address and also puts the sign in the third word. XFLT takes the nulmber in this form and converts it to the program's floatitng point form. 4. 2. 21 XSIN, XCOS: Fixed Point Sine and Cosine These are Varian supplied routines which compute the sine and cosine of the angle in the A register and return the resul t. in the A register. See the Varian manuals for details on scaling. 4. 2. 22 AVG: Fixed Point Averaging This routine is used to -n....(l, out the values used for the antenna calculations. The arguments are a new value in the A register, the old value in the B register and a weighting factor (n) in the X register. The result, returned in the B register, is the value of the expression (B (X-i)+A)/X, where A, B, and X represent the numbers in those registers. Thus, this is a weighted average found by taking n - 1 parts of the old value and one part of the new value and dividing the sum by n. Note that if n is 1, the answer is equal to the new value or if n is 2, the answer is the normal. Uiil" ii c. average of the old and new values given. 4. 3.0 Ilitial i/ atiill This section of code simply sets up pointers and prepares the computer and teletype for the regular program run. It is entered whenever the program is started (at location 0200), whenever the control code 'R' is used and whenever the program is re-started after control code tH' is used. 44

4. 3. 1 MLOOP: Main Program Loop (Fig. 6 ) This is the main processing loop of the direction finder system. It calls on DF 2. 6 (TTIN) to handle teletype input and uses the subroutines already covered in part DF 1. 6 to process antenna data. Each call on TTIN processes not more than one input charllacter and if output is produced, TTIN returns rather than waiting for the teletype to finish printing a previous character. The output is completed on subsequent calls to TTIN whenever the teletype is free. If sense swaitch 1 is on, then antenna data processing immediately follows each call on TTIN. If sense switch 1 is off, then the data is processed only once each time sense s\ itch 2 is itl'l..,1l on and then off. The first itlrlUc-itionl during the scan of the antenna data is to move the values corresponding to each anltetiia from the A table (ATAB) into the B table (BTAB) and at the same time set any negative values to zero. Once the values are in BTAB they will not be changed by the interrupt routines, and therefore a c olml)plete scan can be made of the one set of numbers. A search is made to find the largest signal p)resent. If this signal is lower tlhan the value specified by the tJ' control code (stored in T1+4) then transfer is made to LOSG and the entire set of values is ignored. If the signal is large enough, then the data will be processed. The counter at T1+9 is reset to the value entered with the control code 'Q' (in T1+8) so that the next time a low signal is found, the full delay will be used before the displays are blanked. The highest signral is multiplied by the value entered with the 'K' control function and divided by 1000 and then compared with each of the lantena levels. If any level is less than this, then that level is set to zero. 45

B i\ START -- -! LINK i INI-.....t -.......I INITIALIZE I - _... -- CALL TTIN -- -- j I r Y c i i r t I S — SS1 ON? 'ES NTO NO ' NO <cSS2 ON -. YES MLC = 0 CALL TTIN I2 'O? YES SS2 ONTS'? - ----- NO MOVE ATAB TO BTAB i I. II i i r — -- --- - QCTR = QCTR-1 C — NO ---- TR<0O? YES BLANK AZIM. 4 AND ELEV. I I I! i I I — 1.! -- 66 --- FIND HIGHEST SIGNAL "-____ (HISIG) L -:- IS NO. II ISl.; GREATER -<-_THAN 'J' VALUE? 1 YES 'A FIG. 6a: FLOW CHART FOR MAIN LOOP.

A J QCTR = 'Q' VALUE KCO = 'K' value HISIG/1J000 u-..... =.. FOR -- rSET THAT LEVEL,NO / EACH ANTENNA -- --.-4IS LEVEL GREATER — TQZERQ - THAN / KCO? YES AVERAGE EACH ANTENNA LEVEL WITH PREVIOUS I COMPUTE X,Y,X comll(ponlleint AiD SUMS HYP = SQRT (X2+ Y2) AZIM. = ATAN (Y/X) 'ELEV. = ATAN (HYP/Z) C ORRECT ELEVATION f_... 'MLC = MLC-1 "-r N --- NO- MLC <09?._ ^_YES DISPLAY NEW AZIM. ANLI ELEV.. g 1! I --- —- - --- - * ----1 B ' - LC = 'M' VALUE! _...YES.- -< '-SPTR > AEST + 10? 'I _ NO -SAVE AZIM. AND ELEV.! FIG. 6b: FLOW CHART FOR ANTENNA SCAN OF MAIN LOOP. 47

TTIN J YES.- UTPUT WAITING? --- -NO NO <INNPUT IN BUFFER-:? '-YES -- IS --- NO < CHAR CONTROL -CODE OR DIGIT = YES GO TO PROCESSOR RETURN hI -- YES PRINTING - CHAR-?_ NO TYPE H. CHAR. - - I#-<- - i YES YE S -< TTY BUSY? NO TYPE OUTPUT CHAR. — O. I I I I I I -— I II -— OUTPUT REQUEST-? TU NO RETURN - - i. -- YES. --- MORE OUTPUT? -N0 RETURN TO -. PROCESSOR RETURN I FIG. 6c: FLOW CHART FOR TELETYPE PROCESSOR. 48

Next, the signal on each antenna is averaged with previous levels on the same element. The subroutine, AVG, is used with the weighting factor given with the control code 'F' (stored in T1+7). Each entry in BTAB (multiplied by sixteen) is averaged with the corresponding entry in the U table (UTAB) and the result stored back in UTAB and in BTAB (divided by 16). Now the signal from each element is broken up into its X, Y, and Z cO!pu!l lll by multiplying each:itlillna value by the corresponding values in the X, Y, and Z coefficients tables. These components are each added to the corresponding sums using double precision addition to form the comlposite components. Each of these is converted to floating point. The square root of the sum of the X and Y comlponents is computed and stored in HYP. The azimuth angle is then the arctan of the Y component divided by the X component, while the elevation angle is the arctan of HYP over the Z component. The elevation result must then be corrected for the lack of antennas on the lower hemisphere by using the piecewise linear apprloximsation whose break points and slopes are stored in the W table (WTAB). The first four entries are the differences in the brieahllpoinlts in terms of the computed elevation, the second four are the nu1 r Ill iatutrsl of the slope up to the break point, the thllird four are the denominators of the slope and the last four the values of the break points at the lower end of the linear section in terms of the corrected angle. The differences are subtracted successively from the computed elevation angle until the result goes negative. Then the last difference is added back and the sum multiplied by the corresponding IlllleraLtor, divided by the (lenollinator and added to the lower break point to form the corrected elevation angle. 49

At this point the counter in MLC is decremented. If it goes negative, then the currently computed values for the azimuth and elevation are displayed on the NLXIE tubes and MLC is reset to the value entered with the 'M' control code which is stored in MLC+1. If the counter is positive, the displays are not changed. The pointer SPTR points to a location in the table, AEST. It is set to the beginning of the table each time the control code 'G' is used and incremented once each time the anlllcnlll data is fully processed until it reaches the end of the tables. Since the current azilmutl and elevation are stored in AEST each time the pointer is incremented, the ten successive values are available for use by the 'GI control code processor as soon as the pointer reaches the top of the table. 4.3.2 LOSG: Low Signal Condition Each time that it is found that the highest level signal is less than the 'J' value, the counter in Tl+9 is decremented. If the counter becomes negative then the azimuth and elevation displays are blanked. If the counter is not negative then the displays continue to register the angles for the last signal observed. Since the counter is initialized to the 'Q' value each time a good signal is found, this count down determines how long the display remains lighted after the signal is gone. 4.4.0 LINK DF 2.6 This section of code serves to link the two separate assemblies together after they have been loaded. It stores the address of TTIN, which is in DF 2. 6, in those places where it is needed in DF 1. 6. The addresses needed from DF 1. 6 are stored in a table following the call on LINK (loc 3000) while the addresses needed from DF 2. 6 are assembled into the code. 50

4. 4. 1 TTIN: Teletype Input Processor Each time a character comes in from the teletype, it is stored in a buffer by the illterl''ult time routine, TTYH, Each time TTIN is called and there is no outl)ut waiting for the teletype, the next character, if any, is taken from the buffel and examined. If a character is found, and is either a decimal digit or one of the control codes found in the table, TTAB, then the appropriate pi'ocessor is entered. Otherwise, the character is typed out if it is non-printing or ignored if it is a printing character. 4.4. 2 TCAR, TCBR: Teletype Output Control Each time one of the lpcl'e)'.ss)ors. in DF 2.6 wants to print something out on the teletype, it ca~lls TCAR with the output in the A register or TCBR with the output in the B register. Two chalacteris can be typed from the register; the low order eight bits first then the high order eight bits. If the high order bits are all zero, only the low order bits are printed. If the teletype is busy printing when an attempt to print something else occurs, all three high speed registers are saved and control returned to the program that called TTIN. The next time TTIN is called, a check is made to see whether there is somlethiiing waiting to be printed out, as evidenced by the fact that loatction TOCH is non-zero. If something is waiting, but the teletype is still busy, TTIN returns immediately. Otherwise, the new character is printed. When the output from a call on TCAR or TCBR is finally completed in this Ilmanner, the subroutine returns to the processor which originally callle for output. Note that the ESC control funlction inhibits further print out simlply by storingi a zero in location TOCH and thus may not have the desired effect if it occurs during the control code p)rocessillng before the output routines are called. This, hloweveer, seldom occurs and does not cause any trouble. 51

4. 4. 3 PRAD: Decimal Printout The number in the A register is printed out as a decimal integer. If it is negative a minus sign is prinlted but if it is positive, no plus sign is given. PRAD uses BNBC to convert the number to BCD and then converts each digit to teletype code by adding 0260 octalto the BCD code. 4.4.4 SNCS: Special Sine and Cosine This subroutine computes the sine and cosine of the angle in the A register divided by the scale factor at location TPSF, the latter being the value stored by the use of the I S control code. The angle in the A register is in degrees and the sine is returned in the A register with the cosine in the B register. 4.4.5 GADR: Get Table Address GADR computes the actual address of the location of the table entry given by the element number in EL (stored there by the use of the T', control code) and the displacemenet of the table from the A table in EL+1 (stored as the result of the use of one of the table specification codes 'A', 'B', 'X', etc. ). This address is returned in the X register. A check is made to see that the element number is greater than zero and less than or equal to the iiuinbce of elements as specified by the value in NANT which is set by the 'N' control code. If EL is outside this range, a normal return is not made, but rather control is given to the address specified in the calling sequence. Note that the number in EL is incremented after it is used by each all on GADR. 4.4. 6 GTNM: Get Input Number A call on GTNM returns in the A register the value of the current input number which has been accumulated as digits were entered. It also resets things so that when more digits are typed in, they will begin forming a new number.

4.4. 7 SACN: Store as Current Number and Print The number in the A register is stored as the current input lnumlber and also printed on the teletype. If anythlig has already been typed in as the current number, it is lost. 4.4.8 VSOP: Store or Print Variable This section of code is used by many of the control codes which set or print the value of a simple variable parameter. At the time the JMP to VSOP is l:tmade, the A register should contain the address of the variable to be referenced. If there have been digits entered as the current input number. then that value is stored at the address given and the control letter is printed out. If no current input number exists then the number currently stored at the address given is printed followed by hit control letter. 4.4.9 TTAB: Teletype ( I,,, r.. 1, Table This table conitaiins entries for all the legal control codes recognized by the direction finder system. Each table entry con(sists of two words, the first of which is the 620/i internal code for the teletype character and the second of which is the address of the routine \which processes that character. The end of the table is designated by an entry whose first word is zero. Extra space has been left at the end of the table to allow for the addition of new control codes. 4. 5. 0 Teletype Character Processors Many of the processors which simply use VSOP to store or print the value of a variable and some others which are straight-forward and selfexplnaatory will not be described in detail here since their operation can be easily seen from the assenmbly listings. Note that at the time any of the processors are entered, the A register is zero, the B register has the 620/i internal code for the teletype character and the X register has the number of digits contained in the current input number. 53

4.5. 1 STV: Store or Print Table Entry Each time the cointrol code '/' is used and a current input nulmber exists, that number is stored in the current entry of the current table as determined from EL and EL 41 by GADR. Since GADR increments the table entry pointer, the next time '/' is used to store or print a table value, the new value will be stored in or come from the next higher table entry. Operation when the table value is printed out is slightly different, however. When the entry is printed it is also established as the current input number and the table pointer which was inlcreenlltecl by GADR is decremented by STV so that it still points at the same entry. Thus, if a table entry has been prillted out and it is desired to change it, the current number must be deleted, the new value entered and a '/' typed to store the new value. 4.5. 2 DIG: Digit Entry Processor DIG is entered from a different place than the other processors and in a manner such that the A register contains the numerical value of the digit typed in. Since the multiply instruction on the 620/i adds the A register to the product when it is executed, it provides a very easy way to accumulatllte a decimal number. The accumullated number is in INUM, the sign is in INUM+1 and the count of the number of digits in the number is in INUM+2. 4.5. 3 EQLS: Complete Table Listing When a lquesticoll mark is typed, all the entries of the current table are printed out. This routine prints the letter:: _-c ialted with the table, then '1' to indicate that the first entry follows and then loops printout each of the entries. After nine entries have been printed, a carriage return and line feed are given to insure that there is room for all the digits to be printed on the teletype paper. 54

4.5.6 A: Select Table Whenever any of the control codes which specify a table to be used is typed in, this routine computes the displacement of the table from the A table and ~, *.. it in EL+1 so that GADR can use it. The character associated with the table is stored in EL+2 so that EQLS can use it. The codes involved are 'A', 'B, 'P', 'T', 'U', 'W', 'X', 'Y', 'Z'. 4. 5. 7 C: Calculation of the X, Y, and Z coefficients When the 0 and 0 tables are changed, there is no immlllediate effect on the antenna calctlation because these tables are not used directly. In order that the information in these tables be used, the control code 'C' must be given. This causes the angles in the 0 and 0 tables to be used to compute coefficients stored in the X, Y, and Z tables which are used by the antenna data processing loop. The prolgramt uses SNCS to compute the sine and cosine of each of the angles and from these computes the desired coefficients. 4. 5.8 DBUG: Debug Routine Entry During debugging of the pirogr:iml it is useful to be able to easily transfer to the debug routine. The control code 'CTRL-D' provides this ability. N m!nailly, the program will ignore this code but if the address in the JMP instruction is changed to that of the beginning of the debugging routine then the interrupts will automatically be turned off and the routine called. 4. 5.9 G: Print Hi, Lo, and Average of 10 Scans Every time the control code 'G' is recognized, the pointer, SPTR, is reset to the beginning of the table, AEST, where the azimuthtl and elevation angles are to be saved The 'G' processor then waits for the ten values of each to be stored by typing out RUBOUT's until SPTR has been incremented enough by the antenna data processing loop. Then the subroutine PHLA is called to type out the high, low, and average of the ten entries each of azimuths and of elevations. 55

4. 6.0 Note on the Tapes Supplied with the System Both source and object tapes for the direction finder system are supplied along with various source and object tapes from Varian which come with the computer. There are two forms of object tapes for the direction finder program. One is marked 'direction finder - with corrections - complete'. This contains all the code needed by the program and includes correct values in all the tables and parameters. It may be simply loaded using the regular 620/i loader and run (start at 0200). The other form consists of three separate tapes. Two are the object tapes produced by the assembler and are labeled 'DF 1. 6 (DAS) and 'DF 2. 6 (DAS)'. The third tape contains corrections to these first two and is labeled 'corrections to DF 1.6 and DF 2. 6'. Note that there are four corrections involved and that they have been made in the source tapes and listing. To use the second form. load the tapes into the compulll:ter in the order names above and start at location 0200. Once this has been done and the program is running, the tables and parameters may be initialized from the tape marked 'SETUP'. by placing the tape in the reader and turning it on. The source tapes consist of 17 tapes for DF 1.6 and 11 tapes for DF 2. 6, each tape identified by 'DF n. 6 (m)', where n is either 1 or 2 and m is the sequential tape number. Each tape ends with a 'MORE' pseudo-op so the assembler will stop there. The last tape in each asembly has the 'MORE' followed by an 'END' statement to complete the assembly. Each tape makes a one page listing when printed on the teletype and all the tapes may be combined together to make one long tape. 56

ASSEMBLY LISTINGS 57

PA-GE 000001 * DF 1.6 (EC118) * EQ'J' S 000001 000002 0000/10 000140 000340 0003/1,0 0005/40 000057 000056 000044 000054 000055 000046 000047 000051 000050 * INTERRTTPT TAOCS (1I) RX RB P IM PIC PI N P1ICM. PIF P1I1 ADC A D N ADCB PDN PDF C L KN, CLKF DI SE D I SA P E0tl i F TJ o,EO()T T oF,EQ)TTI,EQ.-0T T,EOTT,vEQTT,E FQTT,vEQTT,E FOTT,v EQTJ.t0 1,p02,P0 40,s0 140,t0240 90 3 /10,0/ 40I.0 0540,v0 57,v0 56 v0 A44,v054,p05 5,p046,t04 7,P05 1,t050 P(SM IN\T MSK CLR IN\JT MODUJLE PflM INT ON PrlM IN\T CLR/ON PC-M INT OFF It\IT PGM INT MOD A/D CINPT) AI/D ON AID BTTSY ( SEN) PEAK DET. ON P/D OFF CLOCK ON CLOCK OFF ELEV DISPLAY AZIM DISPLAY 000000 000000 000001 000002 000003 000004 000005 00000 6 000007 000010 000011 000012 000013 000200 000200 000201 00OP020 000203 0002-04 000205 0002-06 000207 000210 000211 000212 002000 000736 -002000 000757 002000 001037 002000 001050 005000 005000 002000 000660 000020 000040 002000 003000 001000 002020 002062 002074 000000 001070 001 762 001723 000000,O 0RG v 0 ILOC pJM.PM PCLOK,o JMPM,5.TTp R R R R P JMPM,5TIP7 Jr4PM P ECON LINE 01 - CLOCK 0 2 - AN7T EMNNA SW1 -03 - ZERO STW 04- A/D DONE 05 - TTY DONE (IGNORED) 06 - TTY H-IT NTO P INP o,JPMl~ l.,TTYH R IAOR YBEGI,020 LTOR YBEGI,040,PORG,0200 YCALL,03000,VJMP PINIT POINTERS LITERALS CLINK WITH PART 2) BEGIN SCAN a a R R R R oDATA,MLOOP+lMLOOP+l1,0 (REF TO TTIN-) oDATA oBNBCoXC0SoXSINo0 (ADR NEEDED BY PART 2) 58

PAGE 000002 000230 * * DF 1.6 (EC 18 ) * * STORAGE * 000230 000000 000231 000000 000232 000001 000233 000114 000234 000000 000235 000000 000236 000000 000237 000000 000240 000001 000241 000000 000242 000372 R 000243 000255 000256 000257 000261 000264 000267 000272 000275 000276 000277 000300 000301 000326 000327 000341 000346 000351 000354 000357 000362 000365 000370 000372 000416 000437 000460 000501 000522 000543 000564 000605 *,BSS.17 000626 000012 000627 000036 000630 000024 000631 077777,ORG,0230 (2) MLC,DATA,00 TPSF,DATA,1 NCS,DATA,100,0 EL,DATA,0,0,0 MANT AUTC SPTR IMSK CCTR SVD SAVR I SVR TSVR E SVR APTR SZCT TOSI TOSP TOS TOSL TI T2 INTJM TOCH XS TM YS1JM Z SJM HYP FATT AEST ATAB BTAB,DATA.DATA,DATA,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS.BSS,BSS,BSS,BSS,BSS,BES,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,BSS,1,0,AEST,10,1,1,2,3,3,3,3,1,1,1,20,2 10,5,3,3,3,3,3,3,2,20,17,17,17 17,17,17 17,17,17 MLOOP COUNTER THETA/PHI SCALE FACTOR NBR CLOCK CYCLES FOR PDN ELEMENT NR, TABLE,LETTER NBR ANTENNAS NBR CLK CYCLES FOR AUTO CYCLE AZIM, ELEV SAVE TABLE PTR I TERRUPT MASK CLK CNTR SAVED AZ IM. & ELEV. SAVE REG SAVE REG SAVE REG SAVE REG ATAB PTR ZERO SW CTR TOS PTR OUT TOS PTR IN TYPE IN STACK TEMP TEMP INPUT NR, SIGN & COUNT TTY OUT CHAR & REG SAVE FATN TEMP AZIM, ELEV SAVE TABLE INPUT TABLE WORK TABLE (ATAB+17) X COEF TABLE (+34) Y COEF TABLE (+51) Z COEF TABLE (+68) PHI TABLE (+85) THETA TABLE (+102) U TABLE (+119) ANTENNA AVGS 1W7 TABLE (+136) ELEV CORR TABLE WTAB *DATA,10,30,20,077777 BREAK POINT (INCREMENTS) 59

PAGE 000003 000632 000001 000633 000003 000634 000007 000635 000000 000636 000001 000637 000002 000640 000004 000641 000001 000642 000000 000643 000012 000644 000067 000645 000132 ** DF 1.6 (EC118) * * ERHLT *,DATA, 13,7,0 MULTIPLY (NIMERATOR) SDATA 1,2,4,1 DIVIDE (DENOMINATOR),DATA,0~10,55,90 ADD (3) 000646 000647 000650 000651 000652 000653 000654 000655 000656 000657 000000 050272 060273 070274 000111 010272 020273 030274 001000 100646 R ERHLT ~ENTR,,STA ~ESVR,STB ~ESVR+1.STX ESVR+2,HLT,0111,LDA,ESVR,LDB ESVR+1 ~LDX,ESVR+2,RETU*,ERHLT ERROR HALT PUSH 'RUN' TO RESTART * TTY INTERPT PROC * 000660 000661 000662 000663 000664 000665 000666 000667 000670 000671 000672 000673 000674 000675 000676 000677 000700 000701 000702 000703 000704 000705 000706 000707 000000 050267 102501 140040 001010 000715 R 140041 001010 000722 R 005311 001010 000727 R 100240 001400 000712 R 070271 030300 120042 055000 005145 140043 001004 000710 R 030044 TTYH,ENTR STA,CIA. SUB JAZ TSVJR,01,=0201 TTY1 S SUB,=031,JAZ T TY1+5, DAR,,JAZ,TTY1 +10 EXC PIN *JSS3,TTY1-3 HERE IF TTY KEY HIT (TTY ) (201=CTL-A) (232=CTL-Z) (233=ESC) (IGNORE CHAR IF SS3 IS ON) SAVE CHARACTER (X+1 TO X & A) ~ STX LDX,ADD, STA. INCR.SUB ~ JAN, TSVR+2 TOSP =0233, O RX.045 ~ =TO SL *+3 ~LDX,=TOS 60

PAGE 000004 000710 000711 000712 000713 000714 00071 000716 000716 000720 000720 000722 000723 000724 000725 000726 070300 030271 010267 001000 100660 010267 002000 000757 001000 100660 010267 002000 001037 001000 100660, STX,LDX,LDA, JMP* TOSP, TSVR+2 TSVR TTYH R TTY1,LDA *TSVR,CALL, SWP FAKE A SWITCH INTERRUPT R R,JMP*,TTYH,LDA,TSVR,CALL,SWPZ.JMP*,TTYH FAKE A ZERO S! INT (CTL-Z) R R 000727 010300 000730 050277 000731 005001 000732 050351 000733 100240 000734 001000 000735 000712 R * * DF 1.6 (EC118) * CLOCK IN PROC,LDA, STA * TZA ~ STA EXC JMP ~ TOSP,TOSI TOCH PITY1 ~TTY1-3 CLEAR TTY BUFFERS (ESC) (4) 000736 000736 000737 000740 000742 000742 000743 000744 000746 000747 000750 000751 000752 000753 000754 000755 000756 * 000000 050264 040256 010256 140233 001002 000751 R 010264 100240 001000 100736 R 100055 010045 050001 100056 001000 000745 R CLOK,ENTR, STA, INR,LDA,SUB.JAP CLK1,LDA,EXC PJMP*,EXC,LDA STA ~EXC JMP, I SVR,CCTR,CCTR,NCS ~*+6, I SVR,PIN,CLOK,PDF, =AJTT,1,ADN *CLK1 * ANTENNA SWITCH INTERRUPT PROCESSOR * 000757 000760 000761 000762 000000 100054 100047 050264 SWi.P ENTR,,EXC,PDN,EXC.CLKF. STA I SVR 61

PAGE 000005 000763 000764 000765 000766 000767 000770 000771 000772 Q00773 000774 000775 000776 000777 001000 001001 001002 001003 0010041 001005 001006 * ATTTT: 060265 020234 005001 001020 000773 R 050256 001000 000776 R 020256 050256 170046 100046 060233 020047 060001 010264 020265 100240 001000 100757 R ATJTO CYCLE ~ STB,LDB, TZA,JBZ I SVR+ 1,NCS+1 J *+5,STA,CCTR,JMP,*+5,LDB,STA,DIV EXC ~ STB LDB STB,LDA LDB EXC JMP*,CCTR,CCTR.=3,CLKN,NCS,=CLOK,1 I SVR, I SVR+1,PIN, SWJP * 001007 000000 AUT 001010 050264 001011 040256 001012 010241 001013 001010 001014 001031 R 001015 140256 001016 001004 001017 001024 R 001020 010264 AUT 001021 100240 001022 001000 001023 101007 R * DF 1.6 (EC118) (4A) * ATTT (CONCL.) * T, ENTR STA, INR,LDA JAZ I SVR,CCTR,ATTTC,AtTT1,SUJB CCTR,JAN,*+6 2,LDA,EXC,JMP* I SVR,PIN,AUTT 001024 001025 001026 001027 001030 001031 001032 001033 001034 001035 001036 010264 002000 000757 R 001000 101007 R 010234 001010 001020 R 100047 001000 001020 R,LDA I SVR.CALL, SI.TP,JMP*,AITT ATJT1,LDA,NCS+1,JAZ AUT2.EXC CLKF JMP,AUT2 * SWTPZ: ZERO SWITCH INT PROC 62

PAGE 000006 * 001037 001040 001041 001042 001043 001044 001045 001046 001047 * 000000 050264 040276 010050 050275 010264 100240 001000 101037 R SWPZ,ENTR ~. STA, I SUR. INR SZCT,LDA,=ATAB, STA,APTR, LDA, I SVR,EXC ~PIN.RETU*,SWPZ * DF 1.6 (EC118) (5) * * A/D CONV INT PROC * 001050 000000 El 001051 050264 001052 102557 001053 057275 001054 040275 001055 010275 001056 140050 001057 140240 001060 001004 001061 001064 R 001062 010050 001063 050275 001064 010264 001065 100240 001066 001000 001067 101050 R CON,ENTR, STA,CIA ~STA* ~ INR ~LDA, SIJB, ST1B ~JAN HERE WHEN A/D CONV DONE I SVR,ADC.APTR,APTR,APTR.=ATAB,NANT,*+4, LDA,=ATAB, STA SAPTR, LDA I SVR,EXC,PIN,RETU* ~ECON * * BNBC - BIN TO BCD CONV * 001070 001071 001072 001073 001074 001075 001076 001077 001100 001101 001102 001103 001104 001105 001106 001107 001110 001111 001112 001113 000000 050261 070263 030051 005002 005001 060262 020261 170052 060261 020262 004544 005344 001040 001111 R 001000 001075 R 010261 030263 001000 BNBC.ENTR P. STA, SAV, STX, SAV,LDX,=4 *TB ~ BNB5,TZA P, STB, SAV:, LDB,SAV: ~DIV,=10 ~ STB,SAV]. LDB, SAVI *LLSR,4, DXR,.JXZ ~*+4 FR R+2 R+ R R R+1 'A' REG HAS BIN NBR WHICH IS TO BE CONVERTED TO BCD JMP. BNB 5,LDA,SAVR RETURN BCD RESULT IN A,LDX,SAVR+2 AND B REGS RETU*,BNBC X REG UNCHANGED 63

PAGE 000007 001114 * * TCTT: * 001115 001116 001117 001120 001121 001122 001123 * 101070 R WAIT & TYPE CHAR 000000 017020 I 002000 001124 R 041115 001000 101115 R TCW ENTR,,LDA*,TCWT CALL,TCAW CHAR IN LOC AFTER CALL IS TYPED, INR * TCVW ~ RETIJ*,TCT, * TCAt: WAIT & TYPE CHAR FROM 'A' REG zkc 001124 001125 001126 001127 001130 001131 001132 001133 001134 * 000000 101101 001132 R 005000 001000 001125 R 103101 001000 101124 R TCAW,ENTR, SEN,0101,*+5 WAIT FOR TTY TO FINISH NOP P,JMP,*-3 OAR.01 JMP*,TCAW (ALLO W INTERRUPTS) TYPE CHAR * DF 1.6 (EC118) (6) * * FATJ: FLOAT ATAN 001135 000000 FA 001136 027021 I 001137 041135 001140 037021 I 001141 041135 00.1142 016001 001143 145001 001144 001010 001145 001260 R 001146 050370 001147 001002 001150 001154 R 001151 005021 FA' 001152 005042 001153 005014 001154 016000 001155 060371 001156 005002 001157 004501 001160 175000 001161 060327 001162 020371 001163 016001 001164 020327 001165 005311 001166 145001 TN ENTR,LDB* IMR LDX* ~ INR,LDA STTB ~ JAZ v FATN FATNA FATN FATN 1, RB 1, RX,FAT1 ~STA jFATT JAP J *+5 T2 TBA v TXB ~ TAX LDA STB ~ TZB ~LASR,DIV STB vLDB LDA LDB ~DAR ~SUB 0, RB FATT+1,1,ORX ~T1 FATT+1 1, RB VT1 * 1 RX 64

PAGE 000010 001167 001002 001170 001175 R 001171 004001 001172 005111 001173 001000 001174 001167 R 001175 140053 001176 001004 001177 001201 R 001200 005001 001201 120054 001202 051203 001203 004100 001204 005021 001205 002000 001206 001571 R 001207 005012 001210 005001 001211 160055 001212 004502 001213 004116 001214 001020 001215 001217 R 001216 005111 001217 020371 001220 050327 001221 010370 001222 001002 001223 001232 R 001224 005021 001225 005042 001226 005014 001227 010056 001230 140327 001231 050327 * DF 1.6 (EC118) * * FATN (CONCL) * JAP *+6 jASLB. IAR,JMP 1 *-4,S!TB.=15 *JAN *+3 ~ TZA,ADD STA,ASRB,TBA,CALL TAB ~ MUL,MTJL.LASR,ASRB,JBZ. IAR,LDB FAT3,STA,LDA, JAP TBA, TXB ~ TAX,LDA, SUJB, STA,=04117 (ASRB 15) *+ 1,**0,XATN,=229.14,*+3,FATT+1,T1,FATT.*+8,=90,T1.T1 (7) 001232 001233 001234 001235 001236 001237 001240 001241 001242 001243 001244 001245 001246 001247 016002 001004 001247 R 015002 001004 001243 R 010327 001000 101135 R 010057 140327 001000 101135 R 010060,LDA,2,RB.JAN J*+12,LDA,2,RX JAN. *+5,LDA,T1,JMP*,FATN,LDA,=180,SUB,T1 JMP*,FATN,LDA.=360 65

PAGE 00001 1 001250 140327 001251 050327 001252 015002 001253 001002 001254 001240 R 001255 010061 001256 001000 001257 001244 R 001260 015000 F 001261 146000 001262 050370 001263 001010 001264 001271 R 001265 001002 001266 001154 R 001267 001000 001270 001151 R 001271 010062 001272 001000 001273 001220 R * * FSQT: FLTNG SQRT * 001274 000000 I 001275 037022 I 001276 041274 001277 015000 001300 001010 001301 101274 R 001302 015001 001303 005002 001304 004501 001305 055001 001306 001020 001307 001313 R 001310 015000 001311 004301 001312 055000 001313 015000 I 001314 002000 001315 001554 R 001316 002000 001317 000646 R 001320 055000 001321 001000 001322 101274 R *DF 6 (EC118) * DF 1.6 (EC118) (C ~ STJB, STA,LDA ~ JAP,T1,T1,2.RX,*-1 1,LDA,=540,JMP,*-10 FAT1,LDA STTB STA ~ JAZ,ORX O,RB.FATT, *+6 JAP,FAT2+3, JMP, FAT2,LDA,=45 ~ JMP,FAT3 FSQT,ENTR,LDX*, INR,LDA JAZ *,LDA * TZB,LASR STA JBZ,LDA,ASRA, STA FSQ1,LDA,CALL,FSQT,FSQT,O, RX,FSQT 1,RX,1, 1RX,FSQ1 0O,RX,1,O,RX,ORX,XSQT,CALL,ERHLT,STA,O,RX,RETU*,FSQT 3) * FMZ FLTNG NORMAL * FNMZ: FLTNG NORMALIZE * 001323 001324 001325 000000 001030 001340 R FNMZ,ENTR, JIF,030,FNM1 (A=B=O) 66

PAGE 000012 001326 004041 001327 004zlz 1 001330 005144 001331 001002 001332 001327 R 001333 00534/ 001334 004477 001335 004141 001336 001000 001337 101323 R 001340 030063 Q01341 001000 001342 101323 R * * FMPY: FLTNG MIlL * 001343 000000 001344 037023 I 001345 041343 001346 027023 I 001347 026000 001350 005001 001351 165000 001352 035001 001353 002000 001354 001323 R 001355 005012 001356 005041 001357 001020 001360 001363 R 001361 037023 I 001362 125001 001363 041343 001364 001000 001365 101343 R * XDCO: DBL PREC C * 001366 000000 001367 005211 001370 001020 001371 001400 R 001372 005222 001373 005122 001374 004041 001375 004141 001376 001000 001377 101366 R 001400 005111 001401 001000 001402 101366 R * DF 1.6 (EC118) ( *,LRLB, LLI.L, IXR JAP,1 1 *-2,DXR ~,LLRL,31 LSRB,1 RETTJ* FNMZ FNM1,LDX,=077777,RETIJ*,FNMZ FMPY.ENTR,LDX*, INR,LDB*,LDB,TZA,MIJL,LDX ~CALL P, FMPY FMPY,9 MPY,O,RB,O,RX 1, RX FNMZ,*+4, TAB ~ TXA,JBZ,LDX* ~FMPY,ADD,,RX ~ INR.FMPY,RETU*,FMPY,OMP XDCO,ENTR,CPA,JB7,,CPB, IBR,LRLB LSRB,JMP*,1,1,XDCO IAR,,JMP* ~XDCO 67

PAGE 000013 *FADD: 0011i03 001404 00 1405 001406 0014107 001410 001411 001412 00 1413 001414 001415 00 t146 001417 00 1420 001421 0011422 00 1423 001424 001425 00I1426 001427 001430 001431 001432 001433 001434 001435 001436 001437 001440 *XDAD: 00 144 1 0011442 00 1443 0011444 001445 001446 00 14470 001450 001451 001452 001453 001454 001455 001456 001457 001460 001461 001462 FLTMG ADD 000000 027024 041403 037024 016001 145001 001002 001420 005021 005042 005014 001000 001407 140053 001004 001424 005001 1200641 05 1427 016000 00/1300 125000 02 5001 04 140 3 001002 101403 004341 005322 001000 101403 I I R R R FADD PEN7R,PLDB*.INR,PLDX* FAD2 PLDA.JAP,vTBA PTXB,PTAX,pJMvP.vFADD IvFADD,pFADD., 1,p RB,p 1p R X,vFAD1I.,FAD2 FADI,STIB,= 15 i*JAlN,9*+3,pTZA PADD.vSTA.vLDA,vA SRA,pADD,pLDB,vIN.#JAP *.p=043 17 (ASRA 15).v0, RB.p0, RX 1, I RX.,FADD.,FADD R PLSRA,1,vDBR l P RETU* P FADD R DBL PREC ADD 071466 007L400 031463 035000 051467 005021 12500 1 006150 077777 005012 005001 005511 007400 121467 125000 041463 031466 001000 000000.pSTX.PROF,pLDX.vLDX,pSTA.9TBA,*ADD A?\ANA I.pTAB.vTZA,pAO FA.*R0F.vADD,pADD.vI N'R,pLDX.0JMP jXDAD+3 DvXDAD,0, 1. PXDAD+4 p077777,0, jXDAD+3,P0 68

PAGE 000014 001463 R 001464 001000 001 465 001441 R 001466 000000 001467 000000 * * DF 1.6 (EC118) * * XSQT: DBL PREC * 001470 041554 001471 041554 001472 007400 001473 001010 001474 101554 R 001475 061567 001476 131570 001477 001010 001500 001503 R 001501 001000 001502 001506 R 001503 131570 001504 001000 001505 101554 R 001506 131570 001507 071563 001510 005006 001511 005144 001512 004442 001513 001022 001514 001511 R 001515 005344 001516 004456 001517 061562 001520 071566 001521 011570 001522 051564 001523 011562 001524 171564 001525 005021 001526 141564 001527 051565 001530 004301 001531 121564 001532 051564 001533 011565 001534 006120 001535 000377 001536 001004 001537 001523 R 001540 031563 001541 021566 001542 011564 001543 001020 XDAD,EQTT,*-1 JMP, *-19,DATA,0,0 (10) SQRT BSQT INMR ~ INR ~ROF JAZ * ~ STB,ERA ~ JAZ,XSQT,XSQT,XSQT XSQT+ 1,XSQT+12,*+4,JM-P,*+5,ERA,XSQT+12,JMP*,XSQT,ERA STX,ZERO ~ IXR LLRL,JIF,DXR,LLRL STB ~ STX,LDA STA SQT1,LDA ~DIV,TBA ~ STJB, STA,ASRA,ADD STA,LDA,ADDI.XSQT+12,XSQT+7,06,2,022, *-2,14,XSQT+6,XSQT+10,XSQT+12,XSQT+8,XSQT+6,XSQT+8,XSQT+8,XSQT+9,1,XSQT+8,XSQT+8,XSQT+9,0377, JAN, SQT1,LDX *LDB LDA, 3BZ ~XSQT+7,XSQT+10,XSQT+8,XSQT-3 69

PAGE 000015 001544 001 5/15 001546 001547 001550 001551 001 552 001553 001 554 001555 001556 001557 001560 001561 001562 001570 * 001551 R 004301 005322 001000 001543 R 031563 021 567 001000 001554 R 001554 R 051562 001004 101554 R 001000 001470 R 077777,ASRA DBR, JMP *LDX,LDB,JMP XSQT,EQtU, STA JAN*,1 ~*-4,XSQT+7,XSQT+11,XSQT *+5,XSQT, JMP,BSQT,BSS 6,DATA,077777 * DF 1.6 (EC118) (11) * * XATN: FIXED POINT A 001571 000000 XAT 001572 002000 001573 001665 R 001574 000001 001575 000272 001576 176053 001577 004633 001600 167552 001601 014500 001602 152536 001603 000000 001604 077777 001605 000000 001606 001000 001607 101571 R * * POLY: POLYNOMIAL EVI 001610 071661 POL 001611 051662 001612 051663 001613 031665 001614 015000 001615 001010 001616 001625 R 001617 021662 001620 006010 001621 040000 001622 161662 001623 051663 001624 005001 001625 051665 POL1 TAN N,ENTR,,CALL,POLY,DATA,1,0272,-01725S04633.-010226,014500,DATA,-025242,0,077777,0,JMP*,XATN ALUATOR 1,STX STA, STA,LDX,LDA, JAZ POLY-4,POLY-3,POLY-2,POLY.0, 1,POLL,LDB,POLY-3,LDAI,040000 MtUL * STA,TZA L ~STA PPOLY-3 POLY-2,POLY

PAGE 000016 001626 005144 001627 015000 001630 001010 001631 001640 R 001632 121665 001633 005012 001634 005001 001635 161663 001636 001000 001637 001625 R 001640 005144 POL. 001641 015000 001642 001010 001643 001651 R 001644 121665 001645 005012 001646 005001 001647 161662 001650 005144 001651 003010 POL 001652 001664 R 001653 125000 001654 005144 001655 071665 001656 031661 001657 001000 001660 101665 R 001661 000000 001662 000000 001663 000000 001664 014012 001665 000000 POL 001666 001000 001667 001610 R * * DF 1.6 (EC118) (12), IXR,LDA, JAZ,ADD ~ TAB TZJA JMP.2 IXR, LDA JAZ ADD, TAB, TZA MT TL, IXR 3, XAZ,ADD IXR ~ STX,LDX,JMP*,0, 1,POL2,POLY,POLY-2,POLL,0, 1,POL3.POLY,POLY-3,POLY-1,0, 1,POLY,*+3, POLY,DATA,0,0,0,014012,Y,ENTR,,JMP,POL1 * XDAB: DBL PREC ABS+SIGN * 001670 001671 001672 001673 001674 001675 001676 001677 001700 001701 001702 001703 001704 00'1705 *c 000000 037025 I 015000 055002 041670 001002 101670 R 025001 002000 001366 R 055000 065001 001000 101670 R XDAB,ENTR,,LDX*,XDAB,LDA O,.RX, STA,2,RX, INR,XDAB,JAP* '.XDAB,LDB,1, RX,CALL,XDCO,STA,ORX,STB, IRX,RETURN*,XDAB 71

PAGE 000017 * XFLT: DBL PREC TO FLT * 001706 000000 XFLT,EN 001707 037026 I,LD 001710 015000,LD 001711 025001,LD 001712 005004,TZ 001713 002000,CA 001714 001323 R 001715 027026 I,LD 001716 056000,ST 001717 076001 ST 001720 041706 IN 001721 001000,RE 001722 101706 R * * XSIN: FIXED POINT SINE * 001723 000000 XSIN,EN 001724 001002,JA 001725 001736 R 001726 121761 ~AD 001727 001002. JA 001730 001733 R 001731 005211,CP. 001732 005111,IA 001733 141761,SIT 001734 001000,JM 001735 001744 R 001736 141761,STT 001737 001004 JA1 001740 001743 R 001741 005211 CP. 001742 005111,IA 001743 121761,AD 001744 004201,AS' 001745 002000,CA] 001746 001665 R 001747 000001,DA 001750 000027 001751 177130 001752 010421 001753 125253 001754 000000,DA' 001755 077777 001756 000000 001757 001000, JM 001760 101723 R 001761 031104,DA' * * DF 1.6 (EC118) (13) *XCOS FIXED POINT COS * XCOS: FIXED POINT COSINE * TR X* A B X LL XF LT, ORX, 1,RX. FNMZ B*,XFLT A 0 ORB X, 1,RB R,XFLT TUJ* XFLT TR, P,*+10 D,*+27 P,*+4 A R B P,*+22,*+8 B,*+19 N,*+4 A R D LA LL,*+14. 1,POLY TA,1,027,-0650010421,-052525 TA,007777770 P*,XSIN TA,031104 72

PAGE 000020 001762 001763 00176 i 001765 001766 001767 001770 001771 001772 00 1 773 001774 001775 001776 001777 o02000 002001 002002 002003 002004 002005 * 000000 001004 001767 R 005211 005111 006120 031104 004201 002000 001665 R 000001 000027 177130 010421 125253 000000 077777 000000 001000 101762 R XCOS ~ENTR. ~JAN,*+4,CPA, IAR,,ADDI,031104,ASLA,1 CALL,POLY,DATA,1,027,-0650,010421,-052525,DATA,0,077777,0 JMP*,XCOS * AVG: ROUTIINE TO DO AVERAGING * 002006 002007 002010 002011 002012 002013 002014 002015 002016 002017 000000 072015 005344 072013 006160 000000 006170 000000 001000 102006 R AVG,ENTR,,STX,*+6,DXR P,STX,*+2,MTJLI,0,DIVI,0 NEtW VALJE IN A OLD (PREV AVG) VALIE IN B WEIGHT (N) IN X RETURN VALUE IN B B=(B*(X-1)+A)/X,JMP*,AVG * N ALZAT * INITIALIZATION * 002020 002021 002022 002023 002024 002025 002026 002027 002030 002031 002032 002033 002034 002035 002036 002037 002040 002041 100540 100047 100055 007400 030044 070277 070300 005301 055000 103150 103151 010065 050255 002000 001115 000224 002000 001115 INIT,EXC,EXC,EXC rROF *LDX ~ STX STX,DECR, STA,OAR,OAR,LDA ~ STA,CALL PI I,CLKF,PDF =TOS TOSI,TOSP,01 (A=- ) 0,RX,DI SA,DI SE 1=0177720 IMSK ~TCW,0224 (PCH OFF) R R DCALL PTCW,0223 (RDR OFF) 73

PAGF 000021 002042 0020/13 002044 002045 002046 002047 002050 002051 002052 002053 002054 002055 002056 002057 002060 000223 005004 070351 070346 070347 070350 070276 070256 020050 060275 010255 103140 100340 001000 002061 ~ T.X STX ~ STX * STX ~ STX, STX ~ STX,LDB ~ STB LDA,OAR ~EXC ~ JMP TO CH. INTIM T I MTT M+ 1 I MTTM+2 S7.CT,CCTR,=ATAB,APTR IMSK,PIM,PICN,MLOOP R * DF 16 EC ) (14) * DF 1.6 (EC118) (14) * 002061 002062 002063 002064 002065 002066 002067 002070 002071 002072 002073 002074 002075 002076 002000 003000 R 001100 002077 R 001200 002071 R 001000 002061 R 005001 050230 002000 003000 R 001200 002073 R MLOOP,CALL,TTIN,JSS1,ML1 JSS2,*+4, JMP,MLOOP ~ TZA ~ STA,CALL,MLC,TTIN,JSS2,*-2 * * PROCESS ANTENNA DATA * 002077 002100 002101 002102 002103 002104 002105 002106 002107 002110 002111 002112 002113 002114 002115 002115 002116 002117 002120 030050 020240 015000 001002 002105 R 005001 055021 005322 005144 001020 002114 R 001000 002101 R 005002 030066 005021 145000 001002 ML 1 LDX,LDB,LDA, JAP,TZA STA,DBR. IXR,JBZ =ATAB,NANT,O RX *+3 17,RX. *+4 MOVE FROM ATAB TO BTAB AND SET ANY NEGATIVE VALUES TO Z,JMP,*-9 ~ TZB,LDX ~ TBA, SUB ~ JAP, =BTAB,ORX,*+3 LOOP TO FIND LARGEST SIGNAL 74

PAF., 000022 002121 002122 002123 002124 002125 002126 002127 002 130 002131 002132 Q02133 002134 002135 * 002136 002137 002140 002141 0021 002143 002144 002145 002146 002147 002150 002151 002152 002153 002154 002155 002156 002123 025000 005145 140066 140240 001004 002116 005021 140333 001004 002405 010337 050340 005001 160334 1 70067 060335 030066 020240 005322 015000 140335 001002 002153 005001 055000 005144 005323 001002 002145 R,LDB ~ INCR ~ STJB, SUB ~ St rB ~ JAN * TBA, STUB, JAN 0, O,RX,045,=BTAB,NANT, *-8,T1+4,LOSG R JMP IF SIGNAL TOO LOW R,LDA,T1+8 STA,T1+9 ~ TZA,MTIL.DIV, STB,LDX *LDB,DBR,LDA ~ ST.rB, JAP,TZA STA. IXR sDECR, JAP Tl1+5,=1000,T1+6,=BTAB NANT 0, RX Tl1+6,*+4,0 RX,023, *-8 LOW ANTENNA VALUE CUTOFF R ZERO FOR LOW VALUE R * DF 1.6 (EC118) (15) * 002157 002160 002161 002162 002163 002164 002165 002166 002167 002170 002171 002172 002173 002174 002175 002176 002177 * 030066 070332 015000 004205 025146 030336 002000 002006 R 030332 065146 004105 065000 005145 140066 140240 001004 002160 R,LDX AVG1,STX,LDA,ASLA,LDB,LDX CALL,LDX STB,ASRB, STB, INCR SUJB, SUB, JAN =BTAB,T1+3.p O., 102,RX,T1+7 AVUG ~T1+3, 102,RX,- 4,O,RX,Q45,=BTAB ~NANT,AVG1 AVERAGE ANTENNA VALUES (IN UTAB) 75

PAGE 000023 002200 002201 002202 002203 002204 002205 002206 * 002207 002210 002211 002212 002213 002214 002215 002216 002217 002220 002221 002222 002223 002224 002225 002226 002227 002230 002231 002232 002233 002234 002235 002236 002237 002240 002241 002242 002243 002244 * 002245 002246 002247 002250 002251 002252 002253 002254 002255 002256 002257 002260 002261 002262 002263 005004 070354 070355 070357 070360 070362 070363 030066 005001 025000 165021 002000 001463 000354 050354 060355 005001 025000 165042 002000 001463 000357 050357 060360 005001 025000 165063 002000 001463 000362 050362 060363 005145 140066 140240 001004 002210 002000 001670 000354 002000 001670 000357 002000 001670 000362 002000 001706 000354 002000 001706 000357 R R T7.X, STX ~ STX, STX, STX * STX * STX,LDX SZ3,T7ZA,LDB,MTJL,CALL STA STB TZA,LDB,MTTL,CALL ~ STA ~ STB TZA,LDB,MTTL,CALL ~STA STB, INCR,STJB,SUB, JAN ~ ZERO SUTMS,XS TM XST!M+1,YSITM,YSTMJ+ 1,.SITM,ZSJTM+1.=BTAB ~ FORM XY,Z SUMS O.iRX, 17,RX,XDADXSUM R R,XSTTM. XSUM+ 1,O,RX, 34,RX, XDAD, YSUM,YSTTM,YST M+ 1 0, RX, 51,RX,XDADZ SUM ZStUM Z STJM+ 1 045.= (BTAB),NANT *SZ3 R R R R R R R R R R R R R CALL,XDABXSTIJM, CALL XDABYSIUM,CALL,XDABZ SIJM.CALL,XFLT, X SUM,CALL,XFLTYSUM 76

PAGE 000024 002264 002000 002265 001706 R 002266 000362 R * DF 1.6 (EC118) * * MAIN (CONT.) * 002267 002000 002270 001343 R 002271 000354 R 002272 000354 R 002273 050366 002274 060365 002275 005001 002276 050367 002277 002000 002300 001343 R 002301 000357 R 002302 000357 R 002303 050330 00'2304 060327 002305 002000 002306 001403 R 002307 000365 R 002310 000327 R 002311 050365 002312 060366 002313 002000 002314 001274 R 002315 000365 R *, CALL XFLT ZSUM (16), CALL,FMPY, XSTUMvXSUM *STA, STB, TZA ~ STA,CALL ~ STA * STB,CALL. STA STB,CALL,HYP+ 1,HYP,HYP+2, FMPY,YSIIM,YSUM,T1+1,T1,FADDHYPT1, HYP,HYP+1,FSQT,HYP 002316 002317 002320 002321 002322 * 002323 002324 002325 002326 002327 002330 002331 002332 002333 002334 002335 002336 002337 002340 002341 002342 002000 001135 000357 000354 050257 002000 001135 000365 000362 030070 145000 001004 002336 005144 001000 002330 125000 005012 005001 165004 175010,CALL,FATN,YStJMXSIM COMPUTE AZIM. R R R STA SVD,CALL,FATN,HYP,ZSUM COMPUTE ELEV, R R R R R,LDX *, SUTB ~ JAN, IXR.JMP,ADD ~ TAB ~ TZA,MIUL ~DIV, = WTAB, 0, RX ~*+5 DO ELEV CORRECTION,ORX,4,RX,8,RX 77

PAGE 000025 0023z13 0023441 002345 002346 0023117 OQ2350 002351 002352 * 002353 Q02354 002355 002356 002357 002360 002361 002362 002363 002364 002365 002366 002367 002370 004201 145010 001001Z 002350 R 005122 005021 125014 050260 010230 005311 001002 002370 R 010257 002000 001070 R 103250 010260 002000 001070 R 103251 010231 050230,ASLA, ST B. JAN, IBR, TBA,ADD, STA,LDA, DA, JAP 1,8,RX, *+3. 12,RX ~ SVD+ 1 MLC,ML2 (ROUND UIP) ('M' COUNTER),LDA SVD,CALL,BNBC,OBR,LDA,CALL,OBR,LDA ML2, STA,DI SA ~ SVD+ 1,BNMBC.D I SE.MLC+ 1,MLC ('M' VALUE) * * DF 1.6 (EC118) (17) *MAN (CNCL * MAIN (CONCL.) * 002371 002372 002373 002374 002375 002376 002377 002400 002401 002402 002403 002404 010242 005014 140071 001002 002061 R 010257 055000 010260 055012 040242 001000 002061 R,LDA,TAX, S.TB, JAP,LDA, STA,LDA * STA. INR,JMP ~ SPTR.= (AEST+,MLOOP, SJD, O RX ~ SVD+ 1, 10,RX ~ SPTR,MLOOP SAVE AZIM & ELEV IN AEST 10) (DON'T SAVE) * LOS HEE IS SGNAL TOO L * LOSr: HERE IS SIGNAL TOO LOW * 002405 002406 002407 002410 002411 002412 002413 0024 14 002415 002416 * 010340 005311 001002 002414 R 005301 103150 103151 050340 001000 002061 R LOSG,LDA,T1+9 DAR, ~ JAP * + 5 ('Q' COUNTER) (BLANK AZIM) (BLANK ELEV).DECR,OAR,OAR ~ STA, JMP,01 DI SA DDI SE ~T1+9,MLOOP 78

PAGE 000026 003000,ORG,03000 003000 000000 TTIN,ENTR ~ (DTTMMY) 003001 001000,JMP*,TTIN 003002 103000 R 000200,END,0200 LITERALS 000040 000201 000041 000031 000042 000233 000043 000326 000044 000301 000045 001007 000046 000003 000047 000736 000050 000416 000051 000004 000052 000012 000053 000017 000054 004117 000055 000345 000056 000132 000057 000264 000060 000550 000061 001034 000062 000055 000063 077777 000064 004317 000065 177720 000066 000437 000067 001750 000070 000626 000071 000404 POINJTERS 000020 101115 000021 101135 000022 101274 000023 101343 000024 101403 000025 101670 000026 101706 SYMBOLS 1 003000 R TTIN 1 002405 R LOSG 1 002370 R ML2 1 002210 R SZ3 1002160 R AVG1 1 002077 R ML1 1 002061 R MLOO 79

PAGE 000027 1 002020 R INIT 1 002006 R AVG 1 001762 R XCOS 1 001723 R XSIN 1 001706 R XFLT 1 001670 R XDAB 1 001665 R POLY 1 001651 R POL3 1 001640 R POL2 1 001625 R POLL 1 001610 R POL1 1 001571 R XATN 1 001554 R XSQT 1 001523 R SQT1 1 001470 R BSQT 1 001463 R XDAD 1 001420 R FAD1 1 001407 R FAD2 1 001403 R FADD 1 001366 R XDCO 1 001343 R FMPY 1 001340 R FNM1 1 001323 R FNMZ 1 001313 R FSQ1 1 001274 R FSQT 1 001260 R FAT1 1 001220 R FAT3 1 001151 R FAT2 1 001135 R FATN 1 001124 R TCAWt 1 001115 R TCW 1 001075 R BMJB5 1 001070 R BNBC 1 001050 R ECON 1 001037 R SWPZ 1 001031 R ATJT1 1 001020 R ATIT2 1 001007 R ATJTT 1 000757 R S'P 1 000745 R CLK1 1 000736 R CLOK 1 000715 R TTY1 1 000660 R TTYH 1 000646 R ERHL 1 000626 R tTTAB 1 000437 R BTAB 1 000416 R ATAB 1 000372 R AEST 1 000370 R FATT 1 000365 R HYP 1 000362 R ZSTTM 1 000357 R YSTJM 1 000354 R XSTJM 1 000351 R TOCH 80

PAG F. 000030 1 0003/16 FR INTITM 0 0003l 1 R T2 1 000327 R T1 1 000326 R TOSL 1 000301 R TOS 1 000300 R TOSP 1 000277 R TOSI 1 000276 R S7CT 1 000275 R APTR 1 000272 R ESVR 1 000267 R TSVR 1 000264 R ISVR 1 000261 R SAVR 1 000257 R SVD 1 000256 R CCTR 1 000255 R IMSK 1 000242 R SPTR 1 000241 R ATJTC 1 000240 R NANT 1 000235 R EL 1 000233 R NCS 1 000232 R TPSF 1 000230 R MLC 1 000000 R ILOC 1 000050 DISA 1 000051 DISE 1 000047 CLKF 1 006046 CLKN 1 000055 PDF 1 000054 PDN 0 000044 ADCB 1 000056 ADN 1 000057 ADC 1 000540 PII 0 000440 PIF 1 000340 PICN 1 000240 PIN 0 000140 PIC 1 000040 PIM 1 000002 RB 1 000001 RX 81

PAGE 000001 * * DF 2.6 (EC118) * * EQUJ'S 000001 000002 000040 000240 000440 000340 * 000110 000120 000230 000230 000230 000232 000233 000240 000240 000242 000243 000255 000257 000261 000277 000300 000301 000326 000327 000341 000346 000351 000354 000372 000416 * * LINKER * 003000 003000 000000 003001 033000 003002 005144 003003 025000 003004 063437 003005 010120 003006 005144 003007 025000 003010 001020 003011 003015 R 003012 056000 003013 001000 (1 ) RX,EQU RB EQTJ PIM ~EQTJ PIN,EQU PIF,EQTJ PICN,EQ1J IAOR,BEGI LTOR,BEGI 0 ORG MLC,BSS TPSF,BSS NCS,BSS EL,BSS NANT,BSS ATJTC,BSS SPTR,BSS ~BSS IMSK,BSS SUD,BSS SAVR,BSS TOSI,BSS TOSP,BSS TOS,BSS TOSL,BES T1.BSS T2,BSS INT T,BSS TOCH,BSS,BSS AEST,BSS ATAB.BSS,01.02 ~040,0240,.0440 ~0340,0110,0120,0230,2,1,2 *3, rI ~1,1, 1 ~10 ~2,2, 1 'l. 1,20.2 10.5.3 3.14,20,17 ORG,03000 LINK ~ENTR.,LDX,LINK IXR ~,LDB vORX STB,LAD1+1,LDA ~=TTIN, IXR 9LDB 0,RX,JBZ,*+5 STA.0,RB,JMP.*-5 LINK,WITH PART 1 (INIT) (REF TO TTIN) 82

PAGF. 000002 003014 00301 5 003016 00301 7 003020 003021 003022 003023 003024 * 003006 R 025001 063174 025002 063245 025003 063251 001000 103437 R,LDB, STB,LDB * STB,LDB, STB JMP*. I,RX LAD2+1.2,RX,LAD3+1.3,RX,LAD4+ 1 LAD 1 + 1 (BNBC) (XCOS) (XSIN) (TO INIT) * DF 2.6 (EC118) (2) * 003025 003026 003027 003030 * * TTIN * 003031 003032 003033 003034 003035 003036 003037 003040 003041 003042 003043 003044 003045 003046 003047 003050 003051 003052 * 003053 003054 003055 003056 003057 003060 003061 003062 003063 003064 003065 003066 003067 003025 003025 003025 000000 000000 001000 103025 R R R INIT BNBC XCO S XSIN,EQTT,EQtU,EQTJ,ENTR,HLT,JMP* R 000000 010351 001010 003037 R 001000 003137 R 010277 140300 001010 103031 R 030277 025000 005145 140121 001004 003052 R 030122 070277 005021 140123 001002 003062 R 140124 001002 003570 R 030125 060341 015000 001010 003106 R 130341 TTIN,ENTR,LDA. JAZ TO CH,*+4 TTY INPUT PROCESSOR. JMP,TCA1,LDA, STIB * JAZ*,LDX,LDB, INCR, SrB, JAN,TOSI TOSP,TTIN,TOSI, 0, RX,045,=TOSL,*+3 (NO INPTUT) (X+1 TO A & X),LDX,=TOS, STX TOSI, TBA,STrB ~ JAP =02 72,*+5 (='9 '+1 ), SUB,=0260-0272,JAP,DIG CHAR WAS DIGIT ~LDX, STB,LDA, JAZ,=TTAB,T2 O. 0RX LOOK FOR CHAR IN TTAB DRTN+2 (END OF TTAB),ERA,T2 83

PAGE 000003 003070 003071 003072 003073 003074 003075 003076 003077 003100 003101 003102 003103 003104 003105 003106 003107 003110 003111 003112 003113 003114 003115 003116 003117 003120 001010 003076 R 005144 005144 001000 003064 R 035001 073102 030350 001000 000000 R 000000 001000 103031 R 005021 140126 001004 003115 R 140127 001004 103031 R 002000 003151 R 001000 103031 R, JAZ,*+6, IXR i, IXR, JMP *-8,LDX ~ STX,LDX J MP,HLT DRTN, JMP* ~ TBA,StTB. JAN,1,RX,*+3, I NTM+2,**0,TTIN,=0241,*+5 GET PROC ROUTINE ADDR GO TO PROCESSOR,STTB,=0340-0241 JAN*.TTIN TYPE ONLY NON-PRINTING CHARS DCD1,CALL,TCBR,JMP*,TTIN * DF 2.6 (EC118) (3) * TCAR: TYPE CHAR IN A REG * 003121 003122 003123 003124 003125 003126 003127 003130 003131 003132 003133 003134 003135 003136 003137 003140 003141 003142 003143 003144 003145 003146 003147 003150 000000 101101 003131 R 050351 060352 070353 001000 103031 R 103101 004350 001010 103121 R 001000 003122 R 101101 003143 R 001000 103031 R 005002 060351 020352 030353 001000 003122 R TCAR ENTR ~ SEN ~STA STB *STX JMP *,OAR,LSRA,JAZ *,0101,*+7 (TTY WTTE RDY),TOCH,TOCH+1 TOCH+2,TTIN,01.8 * TCAR (TTY),JMP TCAR+1 TCA1,SEN,0101.*+4,JMP*.TTIN * TZB, STB LDB,LDX JMP ~TOCH *TOCH+1 ~ TOCH+2 TCAR+ 1 84

PAGE 000004 * * TCBR: TYPE CHAi * 003151 000000 003152 004460 003153 002000 003154 003121 R 003155 004460 003156 001000 003157 103151 R * * PRAD: PRINT A I 003160 000000 003161 00000 003161 001002 003162 003170 R 003163 005211 003164 005111 003165 020130 003166 002000 003167 003151 R 003170 005104 003171 001010 003172 003200 R 003173 002000 003174 003025 R 003175 030131 003176 001010 003177 003212 R 003200 120132 003201 002000 003202 003121 R 003203 005344 003204 001040 003205 103160 R 003206 005001 003207 004444 003210 001000 003211 003200 R 003212 004444 003213 005344 003214 001000 003215 003176 R * DF 2.6 (EC118) R IN B RES TCBR,ENTR LLRL,CALL,TCA16,TCAR,LLRL, 16,JMP*,TCBR REG DECIMAL PRAD,ENTR ~,JAP,*+7 CPA, IAR,LDB,CALL ~ TCBR,INCR,04,JAZ,*+7 (X= ) LAD2,CALL BtNBC,LDX,=5,JAZ,*+12,ADD,=0260,CALL,TCAR,DXR,,JX%*,PRAD, TZA LLRL,JMP, LLRL,DXR, JMP,4 *-8.4 *-14,*- 14 (4) * SNCS: SIN/COS FOR THETA/PHI * 003216 003217 003220 003221 003222 003223 000000 050327 005001 020133 170232 160327 SNCS,ENTR,STA,T1,TZA,,LDB,=040000 DIV,TPSF MUJL,T1 85

PAGE 000005 003224 003225 003226 003227 003230 003231 003232 003233 003234 003235 003236 003237 003240 003241 003242 003243 0032144 003245 003246 003247 003250 003251 003252 003253 003254 * * GADR: * 003255 003256 003257 003260 003261 003262 003263 003264 003265 003266 003267 003270 003271 003272 003273 003274 003275 003276 003277 003300 003301 * * CRLF: * 003302 003303 0044107 001002 003230 R 120134 140135 001004 003236 R 140135 001000 003237 R 120135 005012 005001 160136 004402 050327 002000 003025 R 050263 010327 002000 003025 R 020263 001000 103216 R,LASL,7,JAP,*+3,ADD S!TB ~ JAN,=055000,=026400,*+5 (2PI) (PI ) ~ STTB,=026400,JMP,*+3 ~ADD ~ TAB ~ TZA,MIL,LASL STA LAD3.CALL STA,LDA LAD4 CALL.=026400,=043575,2,T1,XCOS SAVR+2,T1,XSIN,LDB,SAVR+2,JMP*,SNCS GET TABLE ADDRESS 000000 010235 005311 001004 003275 R 140240 001002 003275 R 120240 120236 120137 005014 040235 043255 001000 103255 R 033255 035000 073301 001000 000000 R GADR,ENTR,LDA, DAR ~JAN,EL,GAD 1,STIB,NANT,JAP, GAD 1 ADD ADD,ADD, TAX ~ INR ~ INR,JMP* GAD1 ~LDX LDX. STX.JMP,NANT,EL+1,=ATAB,EL GADR,GADR,GADR,O RX. *+2,**0 TYPE CR-LF 000000 010140 CRLF.ENTR,,LDA,=0105215 86

PAGE 000006 003304 003305 003306 003307 * * DF 2. * * GTNM * 003310 003311 003312 003313 003314 003315 003316 003317 003320 003321 003322 003323 003324 * *SACN: * 003325 003326 003327 003330 003331 003332 003333 003334 003335 003336 003337 003340 003341 003342 003343 003344 * * VSOP 003345 003346 003347 003350 003351 003352 003353 003354 003355 003356 002000 003121 R 001000 103302 R,CALL.TCAR,JMP*,CRLF 6 (ECl18) (5) GET INPUT NUMBER 000000 010346 020347 001020 003317 R 005211 005111 005002 060346 060347 060350 001000 103310 R GTNM,ENTR. LDA,LDB,.JBZ,CPA. IAR,TZB * STB. STB, STB,JMP*. INTM. I NTM+ 1 *+4 (SIGN), INTM INTJM+ 1. INJM+2, CTNM STORE 'A' REGISTER AS INPT NR & PRINT 000000 050346 002000 003160 R 010346 005002 001002 003341 R 005211 005111 005222 050346 060347 040350 001000 103325 R SACN,ENTR. STA,CALL,LDA, TZB, JAP,CPA, IAR,CPB ~ STA, STB. INR, JMP*, INTTM,PRAD, INUM *+6, INTM,INUM+1, I NIM+2. SACN STORE OR PRINT A VARIABLE 004460 001040 003360 R 002000 003121 R 005024 002000 003310 R 055000 001000 VSOP,LLRL,16,JXZ,*+10,CALL,TCAR,TBX, ~CALL ~GTNM,STA ORX JMP DRTN TYPE CHAR STORE VALUE 87

PAGE 000007 003357 * 003360 003361 003362 003363 003364 003365 003366 003367 * * TTAB: * 003370 003371 003372 003373 003374 003375 003376 003377 003400 003401 003402 003403 003404 003405 003406 003407 003410 003411 003412 003413 003414 003415 003416 003417 003420 003421 003422 003423 003424 003425 003426 003427 003430 003431 003432 003433 003434 003435 003436 003437 003440 003104 R 016000 002000 003160 R 010341 002000 003121 R 001000 003104 R,LDA O,.RB,CALL,PRAD,LDA,T2,CALL,TCAR JMP DRTN GET VALUE PRINT IT TYPE CHAR TTY CHAR TABLE 000215 003513 R 000212 003104 R 000254 003507 R 000255 003517 R 000275 003526 R 000257 003541 R 000277 003600 R 000301 003645 R 000302 003644 R 000303 003701 R 000304 003735 R 000305 003745 R 000204 003755 R 000310 004045 R 000337 003766 R 000316 004011 R 000320 003640 R 000311 003763 R 000332 003641 R 000322 003025 R 000323 TTAB,DATA,0215,CR, 0212 DRTN ', ', COMM ' - ',MI NI,DATA, '=',CNM,'/'.STV, '?',EQLS, 'A' A, 'B ',A-I,DATA,'C'C, 'D',D, 'E'E,0204,DBUG 'H*,H,DATA,0337,DLN,'N',N, 'P',A-5,'I ',I, 'ZZ',A-4 LAD 1 DATA,'R',INIT,'S', S. 'T'A-6, 'X',A-2, 'Y'A-3 88

PAGE 000010 003441 004033 R 003442 000324 003443 003637 R 003444 000330 003445 003643 R 003/446 000331 003447 003642 R 003450 000326 003451 003656 R 003452 000325 003453 003636 R 003454 000327 003455 003635 R 003456 000315 003457 004005 R 003460 000314 003461 004001 R 003462 000321 003463 004065 R 003464 000312 003465 004051 R 003466 000306 003467 004061 R 003470 000307 003471 004071 R 003472 000313 003473 004055 R 003474 000000 003475 * * DF 2.6 (EC118) (6),DATA 'V',V, 'U'~A-7, 'W',A-8, 'M',M, 'L',L,DATA I'Q',Q,'0 JJ 'F'F, 'G',GP 'K'KO0 BSS, 10 * * COM:s SET TABLE ELEMENT PTR * 003507 003510 003511 003512 * 006010 000235 R 001000 003345 R COMM,LDAI,EL JMP, VSOP * CR: TTY RETURN * 003513 003514 003515 003516 * 002000 003302 R 001000 003773 R CR,CALL,CRLF.JMP,I 1 * MINU: SET SIGN * 003517 003520 003521 003522 003523 003524 002000 003151 R 010347 005211 050347 001000 MINU,CALL,TCBR, LDA,CPA, STA,JMP, I NTl+ 1, INJM+ 1,DRTN 89

PAGE 000011 003525 003104 R * CNM: TYPE CTTRREN 003526 001040 003527 003104 R 003530 010141 003531 002000 003532 003121 R 003533 002000 003534 003310 R 003535 002000 003536 003325 R 003537 001000 003540 003104 R * * STV: STORE OR PF * 003541 001040 003542 003555 R 003543 002000 003544 003151 R 003545 002000 003546 003255 R 003547 004037 R 003550 002000 003551 003310 R 003552 055000 003553 001000 003554 003104 R 003555 002000 003556 003255 R 003557 004037 R 003560 015000 003561 002000 003562 003325 R 003563 010235 003564 005311 003565 050235 003566 001000 003567 003104 R * * DIG: AC C MTJLATE * 003570 002000 003571 003151 R 003572 020346 003573 160142 003574 060346 003575 040350 003576 001000 003577 003104 R DF 26 (EC * DF 2.6 (EC118) ( JT NBR CNM,JXZ,DRTN,LDA,=' =',CALL,TCAR,CALL,GTNM CALL,SACN, JMP,DRTN UINT TABLE ENTRY STV JXZ,*+12,CALL,TCBR,CALL.GADRTIER,CALL,GTNM,STA,ORX,JMP DRTN CALL,GADR,TIER,LDA,0,RX,CALL,SACN LDA,DAR, STA, JMP,EL,EL, DRTN NBR DIG,CALL,TCBR LDB, INTTM,MTJL = 10 ~STB INTTM. INR INUM+2 ~ JMP DRTN 90

PAGE 000012 * * EQLS: TTY QUEST * 003600 002000 003601 003302 R 003602 010237 003603 002000 003604 003121 R 00.3605 020143 003606 002000 003607 003151 R 003610 005101 003611 050235 003612 002000 003613 003255 R 003614 003513 R 003615 015000 003616 002000 003617 003160 R 003620 020144 003621 002000 003622 003151 R 003623 010235 003624 140142 003625 001010 003626 003631 R 003627 001000 003630 003612 R 003631 002000 003632 003302 R 003633 001000 003634 003612 R SEECT TAB * A: SELECT TABLE MARK PRO C EQLS,CALL,CRLF,LDA ~EL+2,CALL,TCAR ~LDB,=',1',CALL,TCBR INCR ~ STA EQL1,CALL,01,EL, ADR~CR (A= 1),LDA,O.RX,CALL,PRAD,LDB = '/ '.CALL,TCBR,LDA STrB, JAZ,EL,=10 *+4,JMP ~EQL1,CALL,CRLF ~ JMP, EQL1 003635 003636 003637 003640 003641 003642 003643 003644 003645 003646 003647 003650 003651 003652 003653 003654 003655 005111 005111 005111 005111 005111 005111 005111 0051 11 050236 004204 120236 050236 060237 002000 003151 001000 003104, IAR, IAR, IAR, IAR, IAR v IAR, IAR, IAR A,STA ASLA, ADD ~ STA ~ STB,CALL,EL+1,4,EL+1 ~EL+1 EL+2 TCBR (W) ( U) (T) (P) (Z) (Y) (X) (B) (A) (MUL BY 17) SAVE CHAR R R, JMP,DRTN * V TYPE AZ & ELEV * V: TYPE AZIM. & ELEV. 91

PAGE 000013 00* 003657 003657 003660 003661 003662 003663 003664 003665 003666 003667 003670 003671 003672 003673 003674 003675 003676 003677 003700 * 002000 003302 R 010145 002000 003121 R 010257 002000 003160 R 010146 002000 003121 R 010147 002000 003121 R 010260 002000 003160 R 001000 003513 R V CALL CRLF,LDA,=' tA',CALL,TCAR LDA,SVD,CALL PRAD,LDA,= ' ",CALL,TCAR,LDA,=':E',CALL,TCAR LDA,SVD+1 CALL,PRAD,JMP,CR * DF 2.6 (EC118) (8) * * C: CALC X.YZ COEF * 003701 002000 C 003702 003151 R 003703 030137 003704 015146 003705 002000 003706 003216 R 003707 050261 003710 065104 003711 015125 003712 002000 003713 003216 R 003714 050262 003715 005001 003716 160261 003717 004401 003720 055042 003721 005001 003722 020262 003723 160261 003724 004401 003725 055063 003726 005145 003727 140137 003730 140240 003731 001004 003732 003704 R 003733 001000 003734 003773 R *,CALL,TCBR,LDX,=ATAB,LDA,102,RX CALL,SNCS STA STB *LDA,CALL * STA, TZA MtJL ~ LASL, STA ~ TZA,LDB,MTJL LASL STA I NCR SJB,SUB ~ JAN, SAVR,68,RX,85,RX ~ SNCS ~ SAVR+ 1, SAVR,1.34. RX, SAVR+ 1, SAVR,1,51,RX 045 ~ =ATAB ~NANT,C+3 (THETA) (SIN THETA]) (Z=COSC THETA ) (PHI) ( SINE PHI 3 ) (X) (Y) (X+1 TO X & A).JMP,I1 92

PAGE 000014 * D: DISABLE SWITCH INTERRUPTS * 003735 003736 003737 003740 003741 003742 003743 003744 * 002000 003151 R 010255 110150 103140 050255 001000 003104 R D,CALL,TCBR,LDA,ORA,OAR, STA,JMP. IMSK,=06,PIM, IMSK,DRTN (DISABLE SWITHCES), E: ENABLE SWITCH INTERRUJPTS * 003745 003746 003747 003750 003751 003752 003753 003754 002000 003151 R 010255 150151 103140 050255 001000 003104 R E,CALL,TCBR,LDA, ANA,OAR, STA,JMP, IMSK,=01 77771,PIM (ENABLE SWI TCHS). IMSK,DRTN * * DB!JG: (CTRL-D) GO TO DBUG ROUTINE *c 003755 003756 003757 003760 003761 003762 * 100440 001000 003760 R 100340 001000 003773 R DBUG,EXC,PIF,JMP,*+2,EXC,PICN,JMP,I 1 9).E I,LDA, =AUTC, JMP,USOP ENTER DBUG ROUTINE ADDR WHEN NEE * DF 2.6 (EC118) ( * * I: SET AtJTO CYCL * 003763 003764 003765 * 010126 001000 003345 R * DLN: DELETE CURRENT NBR * 003766 003767 003770 003771 003772 003773 003774 003775 003776 003777 004000 * 001040 003104 010152 002000 003121 005001 050346 050347 050350 001000 003104 R R DLN, JXZ ' DRTN,LDA,=0120337 (SP+LFT ARO),CALL,TCAR I I,TZA, STA, STA ~ STA,JMP, I NUtM I NTTM+ 1, INUM+2,DRTN R * L: SET FIXED PDN TIME 93

PAGE 000015 004001 004002 004003 004004 006010 000234 001000 003345 R R L,LDAI,NCS+1,JMP,VSOP * M: SET MLOOP CYCLE COTTNTER * 004005 004006 004007 004010 006010 000231 001000 003345 M,LDAI,MLC+1 R R,JMP,V'SOP * SET BR ANTENNAS * N: SET NBR ANTENNAS * 004011 004012 004013 004014 004015 004016 004017 004020 004021 004022 004023 004024 004025 004026 004027 004030 004031 004032 006010 000240 R 001040 003345 R 002000 003151 R 002000 003310 R 005012 005311 001004 004037 R 140153 001002 004037 R 060240 001000 003104 R N,LDAI.NANT JXZ, VSOP,CALL,TCBR,CALL,GTNM,TAB,DAR,,JAN,TIER,SIB,=17,JAP TIER ~ STB,NANT ~ JMP DRTN * S: SET THEAT/PHI SCALE FACTOR * 004033 004034 004035 004036 * 006010 000232 R 001000 003345 R S *LDAI TPSF. JMP,VSOP * TIER: TTY ERR PRINT * 004037 004040 004041 004042 004043 004044 006010 000241 002000 003121 R 001000 003513 R TIER,LDAI,'!' CALL,TCAR,JMP,CR * DF 2.6 (EC118) (10) * HALT (PSH RUN TO RESTART) * H: HALT (PUSH 'RUN' TO RESTART) * 94

PAGE 000016 004045 004046 004047 004050 * 100440 000000 001000 000200 H,EXC,PIF,HLT ~, JMP,0200 * J: SET/PRINT LOW SIGNAL CUTOFF * 004051 004052 004053 004054 006010 000333 R 001000 003345 R J,LDAI,T1+4 JMP,VSOP * K: SET/PRINT LOW ANTENNA LEVEL CUTOFF * 004055 004056 004057 004060 006010 000334 R 001000 003345 R K,LDAI,T1+5, JMP,VSOP * SET/PRINT UMBER CYCES AVERAGED * F: SET/PRINT NUMBER CYCLES AVERAGED * 004061 004062 004063 004064 006010 000336 R 001000 003345 R F,LDAI,T1+7,JMP,VSOP * Q: SET/PRINT DISPLAY HOLD COUNT * 004065 004066 004067 004070 * 006010 000337 R 001000 003345 R Q,LDAI,T1+8,JMP,VSOP * G: PRINT HI,LOAVG OF 10 CYCLES * 004071 004072 004073 004074 004075 004076 004077 004100 004101 004102 004103 004104 004105 004106 004107 004110 004111 004112 004113 010154 G 050242 002000 003302 R 010242 140155 001002 004107 R 006010 000377 002000 003121 R 001000 004075 R 006010 ee14 R 1 /35301 002000 003121 R 010154,LDA ~ STA,CALL LDA. STB, JAP, =AEST ~ SPTR,CRLF, SPTR,=(AEST+10).*+8,LDAI,0377 CALL.TCAR,JMP,*-8,LDAI po':A',CALL,TCAR, LDA =AEST 95

PAGE 000017 004114 004115 004116 004117 004120 004121 004122 004123 004124 004125 004126 002000 004127 R 006010 "00147 l 1 35305 002000 003121 R 010155 002000 004127 R 001000 003104 R CALL,PHLA,LDAI ~^':E' CALL,TCAR, LDA - ( AEST+10) CALL,PHLA, JMP DRTN * PHLA: HILO.AVG ROUTINE FOR 'G' * 004127 004130 004131 004132 004133 004134 004135 000000 005014 120142 050342 005001 050343 050344 PHLA ENTR,TAX, ADD ~ STA,TZA,STA ~ STA,=10,T2+1 T2+2,T2+3 (END PTR) (SIM ) (HI) * * DF 2.6 (ECl18) (11) * PHLA (CONCL.) * 004136 010156 004137 050345 * 004140 015000 004141 005012 004142 120343 004143 050343 004144 005021 004145 140344 004146 001004 004147 004151 R 004150 060344 004151 005021 004152 140345 004153 001002 004154 004156 R 004155 060345 004156 005145 004157 140342 004160 001004 004161 004140 R,LDA,=077777.STA,T2+4 PHL 1,LDA TAB,ADD STA,TBA, SUB ~ JAN ~ STB r TBA ~ SUJB, JAP, STB, INCR, STJB JAN,0, RX,T2+2,T2+2,T2+3,*+3,T2+3,T2+4.*+3,T2+4,045,T2+1,PHL1 (LOW ) (SIUM) (HI) (LO) (END PTR) PRINT HI * 004162 004163 004164 004165 004166 004167 010344 002000 003160 010146 002000 003121 R R,LDA,T2+3,CALL,PRAD,LDA,= ',CALL TCAR 96

PA(GE 000020 004170 00/171 004 172 004173 004174 004175 004176 004177 0O4200 004201 004202 004203 004204 004205 004206 004207 004210 004211 004212 004213 * 0103/45 002000 003160 R 0101416 002000 003121 R 005001 020343 1701 42 140131 001004 004205 R 005122 005021 002000 003160 R 002000 003302 R 001000 104127 R,LDA,T2+4,CALL,PRAD,LDA = ',CALL,TCAR,~TZA,LDB, T2+2,DIV,=10, STB,=5 JAN,*+3, IBR,TBA,,CALL,PRAD CALL,CRLF JMP* PPHLA, END,0200 CALC AV (ROUND TUP) LITERALS 000120 000121 000122 000123 000124 000125 000126 000127 000130 000131 000132 000133 000134 000135 000136 000137 000140 000141 000142 000143 000144 000145 000146 000147 000150 000151 000152 000153 000154 000155 000200 003031 000326 000301 000272 177766 003370 000241 000077 000255 000005 000260 040000 055000 026400 043575 000416 105215 120275 000012 126261 000257 135301 000240 135305 000006 177771 120337 000021 000372 000404 97

PAGE 000021 000156 077777 PO INTERS SYMBOLS 1 004140 R PHL1 1 -004127 R PHLA 1 004071 R G 1 004065 R Q 1 004061 R F 1 004055 R K 1 004051 R J 1 004045 R H 1 004037 R TIER 1 004033 R S 1 004011 R N 1 004005 R M 1 004001 R L 1 003773 R II 1 003766 R DLN 1 003763 R I 1 003755 R DBIUG 1 003745 R E 1 003735 R D 1 003701 R C 1 003656 R V 1 003645 R A 1 003612 R EQL1 1 003600 R EQLS 1 003570 R DIG 1 003541 R STV 1 003526 R CNM 1 003517 R MINTJ 1 '003513 R CR 1 003507 R COMM 1 003436 R LAD1 1 003370 R TTAB 1 003345 R VSOP 1 003325 R SACN 1 003310 R GTNM 1 003302 R CRLF 1 003275 R GAD1 1 003255 R GADR 1 003250 R LAD4 1 003244 R LAD3 1 003216 R SNCS 1 003173 R LAD2 1 003160 R PRAD 1 003151 R TCBR 1 003137 R TCA1 1 003121 R TCAR 1 003115 R DCD1 98

PAGE 000022 1 003104 R DRTN 1 003031 R TTIN 1 003025 R XSIN 1 003025 R XCOS 1 003025 R BNBC 1 003025 R INIT 1 003000 R LINK 1 000416 R ATAB 1 000372 R AEST 1 000351 R TOCH 1 000346 R INITM 1 000341 R T2 1 000327 R T1 1 000326 R TOSL 1 000301 R TOS 1 000300 R TOSP 1 000277 R TOSI 1 000261 R SAVR 1 000257 R SVD 1 000255 R IMSK 1 000242 R SPTR 1 000241 R ATTTC 1 000240 R NANT 1 000235 R EL 1 000233 R NCS 1 000232 R TPSF 1 000230 R MLC 1 000340 PICN 1 000440 PIF 0 000240 PIN 1 000040 PIM 1 000002 RB 1 000001 RX 99

SOURCE TAPE LISTINGS 100

-* DF' 1.6 (ECI18) (1I) *EQTT' S RX VEQT1 RB1 FEQTT PIM.EQTJT PIC F.QTT PIN.EQTT PICN PEQTT PIF qEQTI P I1. EQ'T ADC jEQ'1 ADN. EQTTI ADCB PEQTT PDNY EQ IJ PDF.EQTI CLKN PE~tI CL.KF.EQT DISE.EQTI DISA *EQ'T 0 1.,02.p040.0O140.v0240 0 3/10. 0440.v0 540.p0 57. 0 56.044.,0 54.v0955. 046.047 p 051I. 050 P(~m INT MSK{ CLR INT MODYTLE PnM IN\T ON PnM INlT CLR/ON P(rM INT OFF INIT PSM INT MOD A/D (INPT) A/D ON A/D BTISY (SEN) PEAK DET. ON P/D OFF CLOCK ON CLOCK OFF ELEV DISPLAY AZIM DISPLAY * INTERRTTPT LOCS ILOC PJmPM. %JMPM ANIOP P JMPM.r0. SI.YP 0 ECON.pTTYH LINE02 - 03 - 04 05 - 0.1 -CLOCK ANTENNA SW ZERO 51.7 A/D DONE TTY DONE (IGNORED) 06 - TTY HIT POINTERS LITERALS IAOR PBEGI.020 LTOR.BEGI.040 p ORG.00200.vCALL.P amp.PDATA. DATA.P ORG.vMO RE.*03000 (LINK W-.ITH PART 2).,INIT BEGIN SCAN PMLOOP41.MLOOP+1l.0 (REF TO TTIN) PBNBCPXCOSPXSINP0 (ADR NEEDED BY PART 2).p02 30 101

* DF 1.6 (ECI18) (2) * STORAGE MLC,DATA TPSF IDATA NCS,DATA EL DDATA!%VANT DDATA ATITC DDATA SPTR,DATA 3BS5 IMSK,BSS CCTR,BSS SVD,BSS SAVR,BSS ISVR,BSS TSVR,BSS ESVR,BSS APTR ABSS SCT PBSS TOSI PBSS TOSP PBSS TO S,BSS TOSL,BES T I,BSS T2,BSS I NIT TM,BSS TOCH PBSS XSTIM,BSS YSTTM pBSS? STTM,BSS HYP,BSS FATT,BSS AEST,BSS ATAB PBSS BTAB,BSS PBSS,BSS,BSS,BSS,BSS,BSS *,BSS WTAB,DATA,DATA,DATA.DATA DMORE,0,0,1,100,0,0,0,0,1,0,AEST,10,1,1 '3 '3 '3 '3,1,1 o20 22 10 '5 '3 '3 '3 '3 ' 3 '3 22,20,17,17,17,17,17,17,17,17,17 MLOOP CO'TINTER THETA/PHI SCALE FACTOR NJBR CLOCK CYCLES FOR PDN ELEMENJT NRP TABLEDLETTER NBR ANJTENJN3AS NBR CLK CYCLES FOR AHITO CYCLE AZIM, ELEV SAVE TABLE PTR IJTERRTYPT MASK CLK CNTR SAVED AZIM. & ELEV. SAVE RES SAVE RES SAVE RES SAVE RE(S ATAB PTR ZERO) SW CTR TOS PTR OuT TOS PTR IN TYPE IN STACK TEMP TEMP IMPTIT NJRv SIG 'J & COTTNr'T TTY OTIT CHAR & RES SAVE FATV TEMP AZIMi, ELEV SAVE TABLE INPITT TABLE WORK TABLE (ATAB+17) X COEF TABLE (+34) Y COEF TABLE (+51) Z COEF TABLE (+68) PHI TABLE (+85) THETA TABLE (+102) TY TABLE (+119) ANTENNA AVGS W TABLE (+136) ELEV CORR TABLE,10,30,20,077777 BREAK POtINT (IINCREMENTS),p1,3,7,*O MTJLTIPLY (NUMERATOR),1l2v4,1 DIVIDE (DENOMINATOR), O10,55P90 ADD 102

* DF 1.6 (EC118) (3) * * ERHLT * ERHLT,ENMTR ~, STA,ESVR, STB ES.VR+ 1.*STX,ESVR+2,HLT,0111, LDA, ESVR * LDB, E SVR+ 1, LDX,ESVR+2,RETTJ*. ERHLT * TTY INTERPT PROC ERROR HALT PUISH 'RUN' TO RESTART TTYH ENTR ~STA ~CIA STTB, JA7T STIB JAZ ~DAR, JAZ,EXC,JSS3, STX,LDX,ADD,STA ~ INCR, ST]13, JAN ~LDX,STX,LDX,LDA,JMP* TTY1 ~LDA,CALL *JMP*,LDA,CALL.JMP* * ~TSVR,01,=0201,TTY1,=031 TTY1 +5,TTY 1 + 10,PIN,TTY1 -3 T SJR+2,TOSP,=0233 0,RX,045 = TOSL **+3.=TOS. TOSP *TSVR+2 TS SVR, TTYH T SVR SW4P,TTYH HERE IF TTY KEY HIT (TTY) (20 1=CTL-A) (232=CTL-Z) (233=ESC) (IGNORE CHAR IF SS3 IS ON) SAVE CHARACTER (X+l TO X & A) FAKE A SWITCH INTERRUtPT ~ TSVR, SWPZ TTYH FAKE A ZERO SW INT (CTL-Z) CLEAR TTY BTTFFERS (ESC), LDA,TOSP, STA,TOSI,TZA 9. STA TOCH,EXC,PIN ~JMP,TTYI-3 ~MORE, 103

*DF 1.~6 (EC11B) (4) *CLOCK IN PROC CLOK PENTR,PSTA vISVR,PINR *CCTR,PLDA PCCTR,0S!-JB PNCS PJAP,*+6 CLIKi oLDA PISVJR,PEXC,PIN p JMP * PCLOK,PEXC vPDF,vLDA, =ATITT,PSTA,1I,PEXC vADM,PJMP PCLKI1 * ANTEM\JA SWITCH INTERRUPT PROCESSOR SWP, EN TR,vEXC,pEXC.pSTA.#STB,pLDB, TZA,vJE3Z.vSTA.,JMP,pLDB,vSTA.D IV,pEXC.pSTB,vLDB.pSTB,vLDA,pLDB.pEXC,JP 4 *,oPDNI,*CLKF',0I SVJR I SVR+ I,#NCS+ I.9CCTR,vCCTR,G CCTR '0= 3 j,CLKN -PNC S ip= CLO K,01 P I SVR P I SVR+1 P IN P SWP *AU 'TT: AUTO CYCLE AUTT PEN3TR,PSTA,pINR,vLDA,PJAZ P ST B,vJAN. AUJT2 vLDA,PEXC,JP N *,vMORE.9CC TR,PA!TTC DpCCTR.,I SkYR 'PPIN,PAUTT 104

*DF 1.6 (EGliB) (4A) *ATITTT (ClNJCL.),PLDA VISk7R ACALL PSIWP,oJNP* PAIYTTT A1TJ1,9LDA,1JCS+1,pJAZ,A! T2,PEXC PCLKF,JmpPAIIT2 *SWPZ: ZERO SWITCH INT PROC SWPZ PENTR,#STA,ISVR,#IN'R *SZCT.PLDA p=ATAB,PSTA #APTR PLDA vISVYR,*EXC VPIN,RETTT* PSWPZ *MORE 105

* * DF 1.6 (EC118) (5) *A/D CON NT PROC * A/D CON] INT PROC * ECON,ENTR,,STA, ISVR,CIA,ADC,STA*,APTR, I NR,APTR,LDA,APTR. STTB,=ATAB,STJB,NANT,JAN,*+4,LDA,=ATAB ~ STA,APTR, LDA, ISVR,EXC,PIN,RETIJ*,ECON 4* HERE WHEN A/D CONV DONE * BNBC - BIN TO BCD CONV * BNBC,ENTR, *STA,SAVR, STX,SAVR+2 LDX,=4 TZB BNB5 TZA,,STB,SAVR+1 LDB,SAVR ~DIV,=10,STB,SAVR, LDB,SAVR+1,LLSR.4,DXR,JXZ,*+4 JMP,BNB5,LDA,SAVR LDX,SAVR+2,RETTT*,BNBC 'A' REG HAS BIN NBR WHICH IS TO BE CONVERTED TO BCD RETURN BCD RESULT IN A AND B REGS X REG UNCHANGED * * TCWt WJAIT & TYPE CHAR rF TCW ENTR, LDA*,TCW.CALL,TCAW INR,TCTW RETTY*.TCW * CHAR IN LOC AFTER CALL IS TYPED * TCAW: WAIT & TYPE CHAR FROM 'A' REG TCAW JENTR,,SEN,0101,*+5 WAIT FOR TTY TO FINISH,NOP, (ALLOW INTERRUPTS),JMP,*-3,OAR,01 TYPE CHAR,JMP*,TCAW,MORE, 106

* DF 1.6 (EC118) (6) * FATW: FLOAT ATAN FATN PEt\TR,*LDB3*.IM\R,PLDX* VINR,PLDA,# SITST,dJAZ PSTA vJAP FAT2 PTBA,oTXB,PTAX,LDA,PSTB,rTZB,PLASR,PDIV.PSTB iLDB,PLDA,vLDB,PDAR j, ST B.JAP j,ASLB PIAR,PJMP,tSTIB.*JAN joTZA.*ADD -STA,PASRB j,TBA j,CALL s,TAB,PTZA,pMT TL j,LASR PA SRB,pJBZ~ IAR vLDB FATS *STA.pLDA PJAP,*TBA,PTXB,*TAX,*LDA 517T5I,*STA,PMORE,FAThJ,FATMN,FATN,FATNJ 1, I RB,FAT1I,FATT vO.,RB,FATT+1I 0., RX T 1,FATT+lI 1,I. RB T1I 1, RX *4.6,p + 3,p 041 17 3 *+ 1,vXATNJ,=229,v14,v *4.3 xFATT+1,=90 T 1 T 1 I0 (ASRB 15) 1 07

* DF' 1.6 (EC118) * FATN (CONCL) ( 7).#LDA,P JA!\J,#LDA.PJANJ,#LDA 0 imp *,PLDA,51T3T J mp *,PLDA,vST B1,vSTA,vLDA,PJAP,vLDA,. LMP FATI PLDA j,ST JB.vSTA.vJA7Z,vJAP iM,-NP,vLDA,0JMP,2 # 1113,v 2, RX T 1,FATN,=18 0,pT I s FATt',p=360 T1I T I 2,v RX =540.p0, RX.vOv RB,FATT,+ PFAT2+3,vFAT2 '=4 5,FAT3 *FSQT: FLTMG SQRT FSQT PENTR PLDX* PFSQT PLDA PO,#RX,JAZ* PFSQT PLDA P1,RX PLASR PI PSTA,1,1RX PJB7Z PFSQI PLDA P0,RX PASRA PI PSTA POPRX FSQl PLDA POPRX PCALL PXSQT PCALL DERHLT PSTA POPRX,RETTI*,FSQT,MORE 108

*DF 1.6 (EClII) (8) *Ft'JM17: F'LTNG NORMALIZE FNMZ PENJTR PJIF P030PFNM1 (A=B=O) PLLRL PI PJAP,*-2 PDXR PLLR1L,31 PLSRI3 PI PRETTT* PF!N'M7 FNM1 PLDX 0=077777,RETTT* PFNMZ *FMPY:p FLTNG MTVL FMPY PEN3TR PLDX* PFMPY,IN~R PFMPY PLDB* PFMPY PLDB P,ORB PTZA P MyTL DODRX PLDX P1,RX PCALL PFNJMZ PTAB I PTXA PJI3Z,*+4 PLDX* PFMPY PADD v1,RX PINR DFMPY,RETUJ* PFMPY *XDCO: DI3L PREC COMP XDCO PEMTR P,pCPA,vJBZ,vCPB *I BR.vLRLB pL SRB J tMP *.pIAR, JM.P * -PMO RE,.pXDCO ipXDCO 109

* DF 1.6 (EC IB) (9) *FADD: FLTNG ADD FADD PENJTR,LDB* PFADD P I NR v FADD,LDX* PFADD FAD2 PLDA p1,RB,9ST B P I1,RX,vJAP PFADI,vTBA.,vTXB PTAX.,OJMP PFAD2 FADI,ST TB p=15,JAM,*+3 P T7A,vADD,=04317,PSTA,*+2.,LDA.,O.9RB3 PASRA P**O PADD,OPRX PLDB,l1,RX,PIN\R PFADD,JAP* PFADD JLSRA o1 PDBR. PRETT!* DFADD (ASRA 15) * XDADt DBL PREC ADD,pSTX 11 OF oLDX.#LDX,pSTA,vTBA *ADD * ANJAI.9TAB o TZA.,AO FA,o R10F,vADD jsADD I! INR,vLDX "PIPp XDAD PEQTT,pJmp * DATA *MR PXDAD+3,*X DAD PXDAD+4 P, 1 p1,077777 P P0 P P0 PXDAD+4.POP 1,PXDAD PXDAD+3, 0,00 110

* DF 1.6 (EG11B) (10) * XSQT: DBL. PREC SQRT BSQT PINR, INR.RF,PAZ,vSTB,EFRA, JA7,, JMP.,ERA,0 JMP,PERA,PSTX.#ZERO, IXR 9L.LRL,v JI F, DXR,*LLRL.,vSTB,PSTX,vLDA, STA SQTI PL DA,VDIV,PTBA,0STTB3,PSTA, A SRA.*ADD,PSTA,PLDA,#ADDI.PJAN\,*LDX,PLDB,PLDA,0JE3z.PA SRA,vDBR,0 JMP.#LDX,#LDB P ampP XSQT PEQTI P STA # %JAN*,P JMP,!3SS.#DATA.PMORE.*XSQT SpXSQT,vXSQT PXSQT+1 1 PXSQT+12,p *4.5 PXSQT+12.,XSQT PXSQT+12 PXSQT+7,06 PXSQT+6 PXSQT+10 PXSQT+12 PXSQT+8 PXSQT+6 PXSQT+8 PXSQT+8., XSQT+9,01 PXSQT+8 PXSQT+8 PXSQT+9,0377 SQT1I PXSQT+7 PXSQT+10 PXSQT+8 PXSQT-3.1 PXSQT+7 PXSQT+1 1.,XSQT,p +.PXSQT.PBSQT,077777 111

* * DF 1.6 (ECI 18) (11) * * XATNts FIXED POINT ATAN XATN,ENTR.,CALL,DATA.,DATA,JMP* *,POLY 1, 0272,-01725,04633,-010226,014500,-025242, 0, 077777.0, XATN * POLY: POLYNOMIAL * EVALUATOR POL1,STX,POLY,STA POLY,STA ~POLY,LDX.POLY,LDA 10, 1, JAZ,POLL, LDB.POLY LDAI,040C,MT L,POLY, STA POLY,TZA 0 POLL STA, POLY, IXR,,LDA,0, 1, JAZ,POL2, ADD,POLY,TAB P,TZA 0,MTTL,POLY,JMP,POLL POL2,IXR,,LDA 0, 1, JAZ,POL3,ADD,POLY,TAB P,TZ7,A,,MTJL,POLY, IXR p POL3,XAZ,POLY,ADD 0, 1,IXR., STX,POLY,LDX,*+3,JMP*,POLY,DATA 0,OO POLY,ENTR,,JMP,POL1,MORE f-4 C-3 f-2 f-3 )00 -3 r-2 r-2 '-3 P0,014012 112

*DF 1.*6 (EC 118) (12) *XDAB: DBL PflEC ABS+SIGN XDAB PEt'TR,LDX* PXDAE3 L.DA P OPRX,PSTA p2,#RX,pINR vXDAB3,JAP* PXDAB,vLDI3 vlRX PCALL PXDCO PSTA POIRX PSTB,1,RX,vRETTYRN* P XDAB *XFLT: DBL PREC TO FLT XFLT PENTR,LDX* PXFLT,#LDA,O0,RX,vLDB #,1,RX,PTZX. PCALL PFNMZ,LDB3* PXFLT,PSTA vORB3 PSTX l,1,RB PINR vXFLT,RETTJ* PXFL.T *XSIN: FIXED POINT SINE XSIN PENTR PJAP,*+4,vCPA,vIAR. P SUB, *+22 POMP,*+8,vST TB,'*4.1.#JAM v*+4 j,CPA.,PIAR P,pADD,*+14 PASLA PI oCALL PPOLY *DATA 1 O27P -O650O O1O421 PO-52525 JDATA,O,077777,O,JMP* PXSIN DDATA,031 104 *MORE 113

* * DF 1.6 (EC118) (13) * * XCOS: FIXED POINT COSINE * XCOS',ENTR JAN,CPA, IAR,ADDI ASLA,CALL,DATA.DATA, *+4,031104 1,POLY.1 027 -0650,01042 1 -052525.0077777,0,JMP* ~XCOS * AVG RTINE TO AVEAG * AVG: ROUTINE TO DO AVERAGING * AVG, ENTR ~STX,*+6,DXR, STX,*+2,MtTLI,0,DIVI,0 JMP* AVG * * INITIALIZATION 41 NEW VALUE IN A OLD (PREV AVG) VALUE IN B WEIGHT (N) IN X RETURN VALUE IN B B=(B*(X-1 )+A)/X INIT.EXC EXC,EXC ~ROF,LDX STX,STX,DECR,STA,OAR.OAR,LDA STA,CALL,CALL,TZX ~ STX ~STX STX STX STX STX,LDB STB,LDA,OAR EXC JMP,MORE,PI I,CLKF,PDF,=TOS,TOSI, TOSP,01 0, RX,DISA,DI SE (A=-1) =0177720, IMSK,TCt!,0224 (PCH OFF) TCW0J223 (RDR OFF),TOCH, INUM I NTM+1 INTTM+2,SZCT,CCTR =ATAB,APTR ~ I MSK,PIM,PICN MLOOP 114

* DF 1.6 (EC11B) (14) MLOOP PCALL PTTIN PJSSI PMLI,J S2,0*+h1.vJMNP PMLOOP,PSTA PMLC DCALL PTTIN PJSS2,*-2 * PROCESS MLI PLDX,vLDI3,*LDA.,JA P,#TZA oSTA.,DBR oIXR,vJBZ.#1MP ANTENNA DATA * *,TZB,LDX p TBA ASUB,JAP LDB I NCR,ST TB,SUB JAN,TBA,SUB JAN ~LDA STA TZA j,MTUL..,DIV,STB,LDX,LDB,DBR ~LDA SUB,JAP,TZA,STA I XR IDECR *JAP ~MORE p =ATAB.,NANT 0,* RX p1 7.* RX,p +,=BTAB,v0, RX *3 *0, RX p*045.,=BTAB j,NAN T,T 1+4,p LO SG -PT 1+8 PT1+9 ~T 1+5,p=1I000 -PT 1+6,P=BTAB,#NAN T.p0, RX -PT 1+6.p 4.pOp RX,PO23.p MOVE FROM ATAB TO BTAB AND SET ANY NEGATIVE VALUES TO ZERO LOOP TO FIND LARGEST SIGNAL JMP I F S IGNAL TOO LO W LOW ANTENNA VALUE CUITOFF ZERO FOR LOW VALUE * 115

* DF 106 (EClII) (15),pLDX AVG1 PSTX,tLDA.PASLA.,LDB j,LDX,CALL,LDX STB.,AS RB STB,INCR,JAN,TZX,STX,STX STX STX, STX,STX j,LDX SZ3,T7A,LDB j,MTTIL,pCALL jSTA,#STB j,LDB j,MT TL,CALL,STA STB,TZA LDB MT IL,CALL STA ~STB INCR,SUB,STrB JAN *AL,CALL,CALL CGALL,CALL,CALL *MORE,P=BTAB,pTL1+3 op,pRX 'v4 p 102,RX,PT1+7,PT1+3 p1 02,pRX 'p4 p0,9 RX,#045,0 =BTAB,pAVG1I,pX ST TM, XSJM+1I Y ST N AY5ST M+ 1,0Z SIN,0z STTM+ I AVERAGE ANTENNA VALUES (IN TITTAB) Z~ERO SUMS,=BAB FO0RM XPYZ SUIMS.0,0 RX,17, RX.,XDADPXSTJM,0XSTJM+ 1,#34, RX.,XDADPYSTJM J,Y STJM+ 1 0,.RX ip51 P RX,pXDADPZSIJM,? ZST M P zSlim+I,v04 5 #= (BTAB),PNANT,p SZ 3,PXDABPXSTTM,PXDABPYSUJM,XDABZSTJM,PXFLT, XS!TM.PXFLTPY SlIM,XFLT.TPZSITM 116

*DF 1.6 (EC11B) (16) *MAIN (CONT.) PCALL,FMPYPXSUJMXSTJM PSTA PHYP+l P5T13 pHYP PTZA,0 PSTA PHYP+2 PCALL PFMPYPYSUMPYSUM PSTA PT1+l PSTB PTI PCALL PFADDPHYPPT1 PSTA PHYP PSTB3 PHYP4'1 PCALL PFSQTPHYP *CALL PFATNPYSUM*XSUM COMPUTE AZIM. *STA PSkYD oCALL PFATNPHYPPZSUM COMPUTE ELEV. PLDX =WI-T AB DO EL.EV CORRECTION,pST B POPRX PJAN,*+5 PIXR., PJM P,*-w4 PADD POPRX PTAB,0 PTZA A PM~tJ.,4,vRX,pDIV P8PRX PASLA PI,9STIJB,98PRX PJAN,*+3 PIBR,0 (ROUND UP) PTBA.0 PADD P12PRX PSTA oSVD+l PLDA PMLC PDAR,9 (OM' COUNTER) PJAP,9ML2,#LDA sSVD PCALL PBNBC j,OBR PDISA PLDA PSVJD+1 PCALL,I3NBC POBR PDISE PLDA PMLC+1 (IM' VALUE) ML2 PSTA PMLC *MORE p 117

* * DF 1.6 (EC118) * MAIN (CONCL.) (17) SAVE AZIM & ELEV IN AEST,LDA, TAX, STIB, JAP,LDA, STA,LDA, STA. INR JMP.SPTR,=(AEST+ 10),MLOOP (DON'T SAVE) ~ SVD, ORX SVD+ 1. 10, RX SPTR,MLOOP * LOSG: HERE IS SIGNAL TOO LOW * LOSG,LDA, DAR, JAP,DECR,OAR,OAR *STA,JMP *,ORG TTIN,ENTR,JMP* *, T 1 +9,*+5,01,DISA,DI SE T 1 +9,MLOOP,03000,TTIN ('Q' COUNTER) (BLANK AZIM) (BLANK ELEV) (DUMMY),MORE,,END,0200 118

* DF 2.6 (EC118) (1) * EQT'"S RX pEQTJ 101 RB * EQTJ.,02 Pim,EQTI.040 PIN,EQTT P0240 PIF,OEOtJ 10440 PICN #EQTT vQ340Q IAOR PBEGI 10110 LTOR PBEGI,0120,pOR G MLC *BSS TPSF' PBSS NCS PBSS El.,BSS ANt'T PBSS A!JTC,13BS SPTR PBSS,*BSS IMSI{,ESS SVTD PBSS SAVYR PB3SS TOSI PBSS TOSP PBSS TOS,BSS TOSL PBES Ti vBSS T2 PBSS INUM vBSS TOCH- PBSS JBSS AEST IF3SS ATAB PBSS *LINKER,v02 30,1 'v3,P1,10I,p20 '5,o20,172,PORG,903000 LINK PENTR i,PLDX,9LINK,PIXR.,vLDB P,0,RX,PSTB PLAD1+1,PLDA P=TTIN 'VIxa,PLDB v0,RX, B~ 7, *+5,PSTA P,0,RB,1 JM.P,*-5,PLDB v,1,RX j,STB PLAD2+1,PLDB,2,#RX PSTB PLAD3+1,PLDB,3,PRX,PSTB PLAD4+1,JMP* PLAD1+1 *MORE LINK WITH PART 1 (INIT) (REF TO TTIN') (BN.BC) CXCOS) (XSIN) (TO INIT) 119

* DF 2.6 (EC118) (2) I NT I T B3WBC xCO S XSIN P EQTJ P EQTJ,E FQTTI,#ENT TR.,HLT P iJmp*.0 * P * p * p ip jp *. 2 * TTIN TTIN PENTR, vLDA.oJAZ.0JMP.#LDA,#STTIB.vJAZ *,pLDX * LDB.#INCR pSUB,pJAN.#LDX.pSTX,pTOCH.pTO SI.pTO SP,vTTI N.,TO SI 'v0,0 RX,v Q4 5 v=TO St..0=TO S.vTO SI TTY INPUT PROCESSOR (NO INPUT) (X+l TO A & X),TBA,STJB,JA P,SUB,pJAP,pLDX,vSTB,LDA,JAZ,ERA,IXR,IXR.pJMP,pLDX I,pSTX.PLDX.,LrrJIP.#HLT DRTNI JMP*,,TBA P SITB,pJAN J ~SUB,JAN*, DCDI DCALL P,' PJMP*,' PMORE -=0272 (='99+1) -0260-0272 DIG CHAR WAS DIGIT -TTAB T2 OVRX LOOK FOR CHAR DRTN.2 (END OF TTAB) T2 *46 IN TTAB I1PRX *43 INTJM+2 GET PROC ROUTINE ADDR, GO TO PROCESSOR TTIN =0241 *45 =0340-0241 TTIN TYPE ONLY NON-PRINTING CHARS TCBR TTIN 120

* DF 2.6 (EC118) (3) * TCAR: TYPE CHAR IN A REG TCAR PEtNTR,vSEIJ PSTA,PSTB,PSTX.JPim*.,OAR,PLSRA,PJAZ *,PI NLMP TCA1 PSEN,Jmp*.,TZB,vSTB,*LDB,PLDX PJmp PQ1O1,*+7 (TTY WTE RDY),PTOCH PTOCH+l PTOCH+2,PTTIN Ao1 (TTY),p8,PTCAR PTCAR+l,O1Q1,*+4,PTTIN,PTOCH PTOCH+1 PTOCH+2 PTCAR+l * TCBR: TYPE CHAR I N B REG TCBR PENTR,PLLRL.*CALL DPLLRL L JIYP * DpTCAR,v16,vTCBR * PRAD: PRINT A REG DECIMAL PRAD PENTR,PJAP,9CPA vIAR,vLDB,PCALL.INCR,vJAZ LAD2 PCALL *LDX,PADD.#CALL,oDXR.vTZA,PLLRL..,JMP,vLLRL.,PDXR BLIMP IPOR,oTCBR,v04.,BtBC,v=02 60,#TCAR,vP RAD 'v4 'p4 A Iv*-1 (X= 1) 121

* DF 2.6 (EClIBI) (4) * SN'CS: SIN/COS FOR THETA/PHI SNCS PEI\TR,oSTA,PLDB.DI V,vMtJIL,PLASL.,JAP.*ADD.0ST 11,* JAN,pST TB OJMP,PADD,PTAB,vTZA,pMUJL,PLASL,PSTA LAD3 PCALL PSTA,*LDA LAD4 DCALL PLDB P JM NP* p P=040000.,TPSF 'v7,0=055000.0=026400,=02640,9=026400,0=043575,0xCO S PSAVJR+2,vT I,Pxsirq PSAVJR+2.vSmC S (2P1) (PI) * GADR: GET TABLE ADDRESS GADR PENTR.LDA jDARI.vJAN,PSTJIB joJAP,PADD,PADD PADD,PTAX.#INR,t INIR JMPi* GADI PLDX,PLDX,PSTX,RJMP PEL pG AD 1 PNIANT, GAD I,pN AN T,pEL+1I,p=ATAB.vEL.,GADR,pGADR,G SADR.9*+2 * CRLF: TYPE CR-LF CRLF PEt3TR.LDA,PCALL MPjm* *MORE p 01052 15,pTCAR.vCRLF 122

*DF 2.6 (EC118) (5) *GTNM: GET I NPTUT NUMBER GTNM PENTR P,pLDA p INTMU PLDE p,I NTTM+1 ( SIGN) PJBiZ,*+4,PCPA,pTZB P *STB,I NTM,PSTB,INTJN+1I,PSTB,0INTJlM+2,JMP* PGTNM *SACN: STORE 'A' REGISTER AS INPT NR & PRINT SACN PEIJTR P PSTA,9INMTJM PCALL PPRAD,vLDA P INiM,vTZB P,9JAP j,*+6.#CPA P,IlAR,0,#CPB,0,tSTA,IIM!JM PSTB I NTJML+l,PINR,0I NTIM+2 pJMP* PSACN *VSOP: STORE OR PRINT A VARIABLE VSOP PLLRL,16,VJxZ,*+10 DCALL PTCAR TYPE CHAR,PTBX P DCALL PGTNM,PSTA *0ORX STORE VALUE,pJMP PDRTN,#LDA #OPRB GET VALUE PCALL PPRAD PRINT IT.,LDA,T2 DCALL PTCAR TYPE CHAR.JPjm #DRTN *TTAB: TTY CHAR TABLE TTAB, DDATA,O215,CRO212,DRTN,',',PCOr-v'~-V..','MINU PDATA P '=',CNMP 'I'o STVP " '?'EQLSP 'A',Ap 'B' 1A- I PDATA,'C',C,'D',D,'E',E,0204,DB!TG,'"H',IPDATA,0337,DLN,'*N'PN'P',PIA-5 ' I 'pI p'V,1 A-4 LADi- PDATA,'R',INIT,'S',S,'T',A-6,'X',A-2,'Y',A-3.#DATA,''Q''J'',,G,,K,,,PBSS f 1Q PMORE p 123

* DF 2.6 (EClIB) (6) * COMM: SET TABLE ELEMENT PTR COMM,LDAI,EL,JMP,USOP * CR: TTY RETURN CR,CALL,CRLF,JMP,II * MINT!: SET SIGN MINU,CALL JTCBR ~LDA, INIJM+ 1,CPA,,~STA, INUM+1 ~JMP,DRTN * CNM: TYPE CUJRRENT NBR CNM, JXZ ~DRTN,LDA,=' =' ~CALL ~TCAR ~CALL ~GTNM ~CALL ~SACN ~ JMP,DRTN * STV: STORE OR PRINT TABLE ENTRY STV,JXZ,*+12 ~CALL ~TCBR ~CALL,GADR~TIER ~CALL PGTNM ~ STA 0,ORX.DJMP,DRTN ~CALL,GADRPTIER,LDA,0ORX ~CALL PSACN ~ LDA,EL,DAR,,STA,EL ~ JMP ~DRTN * DIG: ACCUMULATE NBR DIG,CALL ~TCBR ~ LDB ~ INTIM,MITL,=1O ~ STB, I NUM ~ INR P I NTJM+2 ~ JMP PDRTN,MORE; 124

* DF 2.6 CEC11B) (7) * EQLS: TTY QTIEST MARK PROC EGLIS PCALL,PLDA.*CALL,*LDB PCALL, IN'CR,PSTA EQLI PCALL.PLDA.#CALL,PLDB,PCALL.PLDA s SUB, JAZ;, JMP.*CALL i JMP 3pC RLF,vEL+2, TCAR,oTCBR,vEL PGADRPCR,vPRAD.,=,I/$,PTCBR.PEL PE QLI1,vCRLF,PEQLI (A= 1) * A0 SELECT TABLE.vI AR,vI AR,oI AR,p IAR,pI AR jo I AR, I AR,*IAR A v STA.PASLA P ADD,pSTA o STB.pCALL. JMP 9 l9 P P.#EL+ I,*EL+2 s TCBR,pDRTN C w) CT )) CT ) ( P) ( 7;) CY) CX) (B) (A) (MUJL BY 17) SAVE CH-AR * V * TYPE AZIM. & ELEVo J#CALL,pLDA,pCALL 9#LD.,CALL joLDA.,CALL,vLDA,*CALL,*LDA,vCALL 's Jmp.vMO RE.ICRLF F=9I: As,pTCAR,PSVJD,vPRAD,pTCAR,vTCAR.,SVD +1,vPRAD,0CR 90 125 I

* * * * * C DF 2.6 (EC11B) (8) C: CALC XoY.,? COEF DvCALL.,LDX p LDA.DCALL,pSTA.pSTB,vLDA.*CALL sSTA.DLA SL.9STA,pLDB, LA SL jSTA vI?'NCR,# ST113.,JAN DU mp,*TCB3R, =ATAB P102,RX P SN~CS.vSAVR,06 8,0RX,85PRX P SAVR+ 1 PSAVJR, 34,v RX jSAVJR+ 1.9SAV7R.91, p9045,p=ATAB,p\1AN T s CI (THETA) (SINICTHETAI)) (Z=COSETHETA3) (PHI) ( SINJCPHII)) (X) (Y) (X+l TO X & A) D E D: DISABLE SI-7TCH INTERR!TPTS.,CALL j,LDA 0 RA.SOAR o STA JoJM.P P TCBR PI MSI{,0=06 tP I M 0I MSIC s DRT\J (DI SABLE SVITHCES) E: ENJABLE SWIYITCH INJTERR'IPTS P CALL P LDA,p AN'A.*OAR,vSTA,vTCBR pI MSK{,v=0 177771,pP IM (EN~ABLE SWI71TCHS) vI MSK{.pDRTM3 * DBfTJG (CTRL-D, DBTJG) vEXC PPIF, JMP p *+2, EXC VPIC' J,JMP,0I11 vMORE ) GO TO DBITS ROTJTINE v EN~TER DBTJG ROrTTIN'E ADDR 'fHiEM N'EEDED 126

* * DF 2.6 (EC118) (9) * * I: SET ATTO CYCLE * I, LDA. =ATTC,JMP,VSOP * * DLN: DELETE CURRENT NBR * DLN JXZ,LDA,CALL I 1, TZA * STA STA, STA, JMP,DRTN, =0120337 (SP+LFT ARO) * TCAR, INTJM. INTJM+1. INTYM+2,DRTN * * L: L * * Mt M * N: * N SET FIXED PDN TIME,LDAI,NCS+1, JMP,VSOP SET MLOOP CYCLE COUNTER,LDAI,MLC+1,JMP ~VSOP SET NBR ANTENNAS,LDAI,JXZ ~CALL,CALL, TAB, DAR, JAN,SI]B, JAP * STB,JMP,NANT ~VSOP,TCBR, G TNM *TIER,=17,TIER,NANT,DRTN * 4, * * S S: SET THEAT/PHI SCALE FACTOR ~LDAI,TPSF,JMP,VSOP * * TIER: TTY ERR PRINT TIER,LDAI.'!',CALL.TCAR. JMP,CR,MORE P 127

* DF 2.6 (EC118) (10) * * H: HALT ( PSH 'RUIN' TO RESTART) * H,EXC,PIF,HLT ~,JMP,0200 * * J: SET/PRINT LOW SIGNAL CtUTOFF J,LDAI,T1+4 JMP,VSOP * * K: SET/PRINT LOW ANTENNA LEVEL CUTOFF * K,LDAI,T1+5 JMP VSOP * * F: SET/PRINT NUMBER CYCLES AVERAGED * F,LDAI,T1+7 JMP.VSOP * * Q: SET/PRINT DISPLAY HOLD COUNT * Q,LDAI,T1+8,JMP.V SOP * * G: PRINT HI,LO,AVG OF 10 CYCLES * G,LDA,=AEST ~ STA,SPTR,CALL,CRLF,LDA,SPTR, STrB,=(AEST+10),JAP,*+8,LDAI,0377,CALL,TCAR,JMP,*-8,LDAI,':A',CALL,TCAR,LDA,=AEST,CALL,PHLA,LDAI,':E' CALL,TCAR,LDA,=(AEST+10),CALL,PHLA ~ JMP,DRTN * PHLA: HILO,AVG ROUTINE FOR 'G' PHLA,E TR,, TAX,,ADD,=10,STA,T2+1 (END PTR) * TZA, STA,T2+2 (STIM) ~STA,T2+3 (HI) PMORE ~ 128

* DF 2.6 (ECliB) (11) * PHLA (CONCL.),vLDA,=077777,PSTA,T2+4 PH*,pLDA,TAB3,ADD,STA,pTT3A p STB,JAN,STB,,TBA,SUB,JAP,STB,INCR,SUB,JAN,pLDA,CALL,LDA DCALL *LDA DCALL,pLDA a CALL,pTZA,*LDI3.#DIV,S U13,JAN,IBR,TBA,CALL.,CALL JMP * ~ T2+2 T2 +2,vT2+ 3,vT2+3 ~T2+4,T2+4 i04 5,T2+lI,PHI I *T2+3 j,PRAD -,9 I,pTCAR PT2+4,vPRAD,TCAR,vT2+2,0=10 '5,vPRAD,vCRLF.,PHLA (LO W) (SUM) (HI ) (LO) (END PTR) PRINT HI CALC AV (RO UND UP) * *MORE.PEND,0O200 129