T H E U N I V E R S I T Y O F M I C HI G A N Memorandum 16 PDP-8 TO 103A DATAPHONE AND/OR ONLINE TELETYPE INTERFACE K.E. Burkhalter, Jr. CONCOMP: Research in Conversational Use of Computers F.H. Westervelt, Project Director ORA Project 07449 Supported Tby: ADVANCED RESEARCH PROJECTS AGENCY DEPARTMENT. OF DEFENSE WASHINGTON, D.C. CONTRACT NO. DA-49-083 OSA-3050 ARPA ORDER NO. 716 administered through: OFFICE OF RESEARCH ADMINISTRATION ANN ARBOR April 1968

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PDP-8 TO 103A DATAPHONE AND/OR ONLINE TELETYPE INTERFACE K.E. Burkhalter, Jr. Further Notes on PDP-8/103A Interface* This report supersedes two previous reports on this subject, and reflects changes incorporated to improve performance (that is, level converters have been added between the PDP-8 TTY lines, and the following logic). The accompanying diagrams illustrate an interface between AT&T 103A data sets and a standard PDP-8 processor and its associated online teletype (TTY).. The interfaces provide: a. connection of the DEC online TTY to the dial switch network; b. connection of the DEC online TTY to the PDP-8; c. connection of the PDP-8 to the dial switch network. Figure 1 illustrates the possible modes of operation. See also, Mills, D.L., Notes on PDP-8/103A Interfaces, Concomp Project internal memorandum, 25 September 1966; and Lundstrom, Stephen F., PDP-8/103A Dataphone Interface, Concomp Memorandum, November 1966. -1

-2Telephone Dial Network 103Ai 103A Datae Set Data eta - -......... PDP-8 Mainframe Connection Switch Figure 1 The interface takes care of interlocking the various features so that chaos can not reign supreme. Thus, the TTY can be used with its data set only if it is not attached to the 8. When the TTY is switched to the PDP-8, terminal ready drops on the TTY data set, disconnecting it from further use, so that contention is not a problem. The reader advance solenoid of the TTY is also brought TRUE at this time, so that the reader may be used with the data set by throwing the reader advance switch, on the reader, on and off. This is necessary since the data set does not have an extra channel available to control the reader, as is the case with the local processor. Note that the terminal ready lead of the

-3mainfraim data set is brought out to a switch so that it may be dropped if necessary to initiate a disconnect (a feature that has often been found handy). The PDP-8 may be switched back and forth between the two I/O devices (TTY, mainframe data set). If, however, either is actively engaged in data transmission, a few garbled characters will result. The interface forces a MARK condition on the unused port so that it will not chatter for the case of the TTY, or space disconnect for the data set. Also, since the switchover is done rapidly and while in MARK states (assuming no transmission) there is no SPACE transition and thus no "burping" of the teletype. The state of the PDP-8 keyboard input and printer output lines is indicated on a lamp panel attached to the logic mounting bays. The lamps light for the SPACE rather than for the MARK state, thus allowing the lights to be normally off. The terminal ready lines of both data sets are also monitored via a front panel lamp each. In addition, as noted before, the terminal ready line for the mainframe data set is brought out to a front panel switch, which will normally be left in the on position. One special board is required for the interface, to restore standard logic levels, since the PDP-8 TTY interface is designed to interface with solenoids rather than with logic gates. The solenoid driver used within the computer is the W050 which produces an output between -2 (on) and

-4-15 (off) volts. To restore these to ground and about -3 volts, a three-diode string (3-IN457As) is added at the printer and reader output leads. The extra IN270 diode on this board is used to pull the mainframe data set transmit lead to the MARK state when the PDP-8 is connected to the TTY.

EIAR T'Y13 807 DT E IKBDI IPTR 1 ~~~~~~~ ~~~TR M RDY TP-TDSRM+ A07 - KBD PTR TTYd E T.DSRM- E, V RE 1 3 DAT P~DP-8 TDSXM- D 2 XM W024 C/R LK D LPTR-1 LTRDY )Ta B05 N1 KEY D BM IwTTYKIVIwso BRD b 0'N 1 I I- I I I - Te~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~vnTRY+ K T0 KBDM- L~ K a'.DSEN.B- 7 TPM~ - — 15~~~~~~~~V OUT.808 +10 Alb B~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ill -15 A 0 0 TTY'EN- T -Is AIO M ~~~~~~~~RDENB- v RDR m RENB+ RENBO+ R K W 33 70 OUT A06Rli TTYPM + RDENB+ I KBDM- II ~ w 810 Ri TTY fN I YEN- H H( I - i( sos I I I 8081 I I~~~~~~~~~~~~~~~~E~ MIVDSRIVI EIAR 807 MAIN R E + %A4"~~~V OS L TO IR losI A~B0,9p~ DSENB_ SWIPE K 89947' N M~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~VDSX D MT L LTRD~~~~~~~~~~~~~~~~~~~YI TRDYI - -f300l DATA CO NC ENTRATOR EXTRAS N 4.47 K.P TRDYI+ K16 TM TT PP8.iTR.M RDY T0 D TTY, PDP-8.& ~~~~~~~~~~ ~~~~~~A10 + 10 I c MAIN 7R RDIS 103A DATA SET INTERFACE IN270 0~ DEC. 26j, 196 7-DSKEB;

APPENDIX

APPENDIX Wire wrap documentation is reproduced on the following pages as a servicing aid to those responsible for that function in the future. -9

WIRE WRAP (VERSION 27 JUNE) INPUT LISTS 1A05 W050 DSEN'B-K LTRDY2L TRDYI-M LTRDYIN TPM-P TTYPM+R RDENB-S 1A05 WO50 K8 M+E LKBDF POMO+H LPTRJ R DEN B-+T 1A06 W070 TTYKM+D TTYPM-+H RDENB+M 1A07 W021 MJ TSXM-D TDSRM-E TRDY2+K 1A08 W602 MDSXM+D MDSXM-F DSENB-H TRDY2+K TTYKM+L TDSXM —N 1A08 W602 TMDS+P TMD"S-R TMDS+S TMDS-V 1A09 R107 TTYEN-K MDSXM+J KBOM-M KBDM+L TDSRM+S TPM-R 1 A09 RIOO'TRDXi+-U TRDY'I-T IA10 W994'T RENB+F RENBO+H POMO+K POM+L MDSXM+N TROY I+P 1A10l W994T SWIPER TRD XI +U 1805 WO21RC KBDM+D POM +H R ENB+M 1806 WO21M- MO-SXN'i —-D-MSRq —E.."TROY1+K S-T-iO+A STDGNDC 1B07 EIAR GTDSR-D G'TDSR-C TDSRM-E TOSRM+J TOSRM+H GTOSR-R 1 807 EiAR MOSPM-S MDSRM+V MDSRM+U 1.808 R111 DSENB+P KBDM-N POMO+R TTYEN-S TTYFN+V TPM-U 1808 Rlll DSENB-D MDSRM+E KBDM-J KBDM-H TTYEN-K TTYKM+L 1809 Rlll TTYEN+D DSENB-E TTYEN-J'TTYEN-H TTYEN-K OSENB+L.1B09 Rlil DSENB-P DSEN8-N RENBO+R TTYEN-S RDENS-'V RDENB-U

-11***** PDP-8 TO TTY/103A ADAPTER **** CONCATONATED CIRCUIT LISTS D SENB+ B09Lr 1OB8P DSENB- 1AO5K, AO0H, 11 80DBO9E 1BO9N, 1BO9P GTD SR- 1BO 7C t 1 070, t 1BO7R KBDM- 1805D,1 AO5,'IAO9L KBDM- 1AO9M, 1 BO8H 1 BO8J,t BO8N LKBD IAO5F LPTR 1A05J LTRDY1 1AOSN L TRDY2 lA05L...'.'OMOSRM +' O' E —'' 1B08ElBt7-.lfl-7V MDSRM- 1B06E, 1B07S.-. MDSXM+'1A 0 8 D' IAO9JI A-1 ON MDSXM- lAOSF,1806D POM+ 1A1L, 1BOS 5H POMO+'1AO5H, 1 AlOK t 1 B 8OR.R iENB'+ I'' AO6-M, M 1AO' ST RDENB- 1A05S,1 09U, IBO9V'-.~_......................i' "A —i.0.F., i.,.'.5 M............................... RENB1 1AOF1R()5M RENBO+ 1 AOH 1BO9R S TD'10+ IB0 6A STOGND 1 BO 6C SWIPE 1 A10 R TD SRM+ IA09S, 18O7H t1BO7J T DSRM- 1 A0 7 E 1 BO07- E TOSXM- 1A07,A soA8N TMDS+ 1AO3P, 1 A': S TMDS- A8R R,.40O 8V TPM- 1AO5P, 1A09RB 1 0 8U TRDXI+ IAO9U I I Al OtU TRDYi+ 1 AIOPt 1 6K TRODY - IA05Mt 1A09T TRDY2 + 1 AO'7K,1 AO8 K TTYEN+ 1B09Dt1BO8V TTYEN- 18 OS 9S IBO 8 S, 1 B-O 8Kv 1 BO9K 1B09H, 1 O89J 1 AO9K TTYKM+'l AO60 1 A08L t 108L TTYPM+ 1AO6HfIA05R

***.* iPDP-8 r1'TTY/t03A AD APTFR **t:4 CROSS-REFERf!ENCE TABLE S (****' DENOTE-S' tLrOC.ATI-ON.F P'IN BEING RFFF.PFNJCF 1A05 E KBDM+ 1. B 050 ** **t t, 1. A091_ 1A 05 F L. KBR n IAO 5H Pi'M3+:*,e 1 AlOK,1 08R IAO5J L PTR "*I IAOSK DSE NB-'*t *, I AO3H, 1BC3OD,80 tO9E, 1BON,1BO9P 1AO5L L TR DY2 TR-'** 1AO5M TRDY1-:4'* A1 9'T 1 A05 N L T R DY I -: -. 1A05 P TPM- **,,t ~AO9R,1 B08U I AO)5 T T YPM + IAC6H,'** 1. A05 S R i)EN f- *** t 19 U 1 B 9V 1 A 5T R i)F.B+ 1 AO6M,* * —** IAC6D ITYKM+ **,1A.., ] I t BO8L lA06H TI'YPM+ I A***, 5 A R AO6MtP RPfE NB+ **4, l 1A0C5T iAO7 1 Do S0M- *S* -t*, lAn9N'1 07 E TDSRM- -.-**, t I 7E AO7K TRDY2+ **'*, 1 l AO 8K 1408 MDSXM4+ *'-t**,1Ao9J,AlO1N IAO-8F moSxm- * * 1 06) A0O8H DSENB- 1 A05K,*****1 BO 8D IB309F 1R 9N, iB09P 1A08K TRDY?+ 1 A: 7K;: 1A08L TTYK'+ 1A060,~***, L tl1Ot I A08N TX)SXM- 1AO 7r),** *'IA 08P T MD $ ****, IAOS -I A 08R T MP'1 S- ****,t1A08V 1408S TMUS+ 1 AQ) P * ***c lA08 V THMS- 1AR ** IA09J MDS XM + 1. AO, *** AI ON 1A09K TT YN- 1 ) 10q-S, 1SK8, 10t OK, 1 09H 1 B09J,:**** IA O9L KBDM+ 1 5~1,a l A05E,'t.t 1 AOg9 M R m' I * 1B Hi B':8 — SJ I B 6',;9-N- 8..N 1A09M K'PDM- *4 *,1,1B08%i,1B0$3n 1AO9R TPM- 1 AAO5 P, ** *,' tl BO38 U 1A09S TnDSRM+ **:*, 1BO 7t-' 1B O'7J 1A09T T RDY'I- 1 A05-M,***, -1 t 1A 09 T R X 1+ *, 1 A 1O'lAlOF RENB+ **,'IBO5M A 10 RE PN {: + 1ASH, 1****, B -R A10K p.J' G + I - ) 5 t tf t*_ 1 5 0 8 R. IAlOL P.OMf+ L****, 1BOSH IAlON MDS XM+ 1 A 080, 1 A09J, s***** LAIOP TR DY+ *****, B 6K 1A 10R SW I PE _ * _ _ IAIOU TRDXI+ A09Ut***** IBOSD K BDM+ * **, 1AO 5 E 1A O9L 1 B 05 H P'oM + 1,L L t* *,...c 1O05M R FN'8+ 1 A1 OF,* 4- 1B06A ST1D.10+ **. 1B 06C S'TOGND O':. -- * # 1B061.) MDS XM-'1 i AOSF, r ~*.t BSO6 f MDSRM- *- -*'1B 0 7S IBO5K TR'OYI+'! A'lOP,* *'*... 1i30)7C G'D SR- *c*,l3 1 BO D, 1 BO 7R [1 Pl0 T7 f D SR-'. 0 7 C, * *. "4:, 1 B 7 R

***** PDP-8 TO TTY/103A ADAPTER ***** 1807E TD S R M- 1 AO7E, ****** 1 B 07H TDSRM+ I AO9S,*** * t 107J 1B07 J T DS RM+ 1 AO 9 S 1 BO 7 H***** 1B07 R G-TDSR- 1 B7C t BO7Dt ***** 1B07S MDS RM- 1 6 E t*****' B07 U M DSRM+ 1BO 8E,***** 1BO 7V IB07V MDSRM4 1 8 E t 1807 tj *** * 1808D DSENB- 1AO 5K, IAO 8H t*****, t BO9E, 1809N, lB O9P.80-8E MDoSRM + t*-***B 107Ut 180 7V 1808H KBDM- 1. A09M,***** 1 808J t 18B0 8N 1808i KBDM- L-A09 lBO 8H,*****t 1BO8N' 1B08K TTY FN- 11B09S, 1B08Sr *****,t IBO9K,'IB09H t 1B09Jt 1A09K' 1.L _ T'TYKM+.. -A' 6D,1AO8L,***** 11808N KBDM- AO9M 1BO8H 188J **t*** ~1808 P'' P''' D-SE''NB-' 1 -,''.**":'-*-*..'''''.''' 1B08R POMo+ I AO5H, 1A l OK, t***** 1B08S TTYEN- 1 B9S ***** 1 BO8K t IBO9K IB09 H 1QBO9JAt AO9K 1BOU TPM- IAO5P 1AO9R,***** 1 80 f30 V TTY EN- + 1 0 9, *** - _ _ __tF 1iB090D TTYEN+ ***** lBO8V__ 1-09E OSfNR- I AO 5K, 1AO8H, lB080 -t,-***** 1BO9N 1BO9 P 1809.H TTYEN1- IBO9S 1BO 8SS tB8K, 1B 9K,*t **** t B09 JIt AO9K 1809J TTYEN- 1 309S,1t80SS,1BO3K, lBO9K1B09H,*****t l AO9K 1809K TTYEN- 1e09S, 1BO 3S, BO 8K,*****, 1BOqH lB09JIAt AO9K 1809N DSENB- 1 AO 5KA 1AO 8Ht lB0D8 1BOg9E,*****, lBO9P iB09P D SE NB- I AO5K -t,AO88Hi1 B 080,B E E 180 809N, t***-** 1B09R REN BO+ 1A1OH,***** lBO9S TTYEN- *****,B sB8St 1808K 1B9KIB9H t 1809J, IA09K 1 809 U RDEN8- IA05S, -*****, BO9V 1809V RD'E NB- 1 AO5S, 1 o8 9U*****

-14**tc** PDP-8'TI. TTY/ 103, AD.PPTFR **$'-OUTPUT LISTS LKBD I AOSF SIN hIrL E I/O OR TEST CONNECTION LPTR J,1A05J S INGLE I/0 OR TFST CONNECTION LTRDYI 1 A05N S N GLE EI/i OR TEST C ONNECTTON L TRODY~2 1AO5L St NGLE I/O OR TEST CONNECTION STD10o+ 1 806A S INGLE I/[ OR TEST CONNFCTION STD-GND 1606C SINGLE I/O OR TEST CONNECT ION SWIPE IAlOP S INGLE 1/O OR TFST CONNECT [ION

-15***** DPP-8 TO TTY/103A ADAPTER ***** BAY 1 -..- BA-Y l.' i"EVEL I TMDS+ 1 001 I A 08P 1A 08S GTDSR — 00. 1lB 07C 1 B 07D DSENB- I 001 IB 08D LB 09E TTYEN- 1 00 1 1 B 09H 1 B 09J DSE NB- 1 001 1 B 09N 18 0_9P TRDY2+ 1 002 1 A 07K 1A 08K TMDS- 1 002 1A 08R 1A 08V TRDXI+ 1 002 IA 09U IA 10U KBDM- I 00 2 lB 08J 1B 08N T.................'.......''I................- -- TTYEN- 1 002 18 08K 18 09K'TTYEN- 1 002 18 08S 1B 09S MDS XM+ 1 003 LA 080 1A 09J R DENB+ 1 003 1A 06M 1A 05T DSF.NB+ 1 003 LB 09L LB 08P TTYPM+ 1 004 1A 06H 1A 05R TTYKM+ 1.005 IA 06D L A 081'TDSXM- 1 005 I A 07D LA 08N DSENB- I 006 1A H'lA 08A 05K MDSRM- 1 006'lB 06E 18 07S MOSRM+ 1 007 L 08F LB 07U TTYEN+ 1 008 1B 090 1B 08V TRDYI - 1 009 1 A 05M 1A9T TPM- 1 009 1A 05P 1A 09R TDSRM+ 1 009 LA 09S lB 07H POMo0+ 1 010 1A 05H IA 10K KBDM- 1 010 LA 09M lB 08H KBDM+ 1 oll A OfE lB 05D TDSRM- I OL1 1A 07E lB 07E M0SXM- 1 012 1A 08F 18 06D TRDY1+ 1 013 1A 10P lB 06K RENBO.+ 1 015'A 10H lB 09R POM+ 1 015 1A 10L lB 05H ROENB- 1 016'I.A 05$S LB 09U RENB+ I 01.9 - A LOF 18 O5M

-16**.*-. PDP-8 TO TTY/1 03 ADAPTERf'***4*: BAY I TO BAY 1, LE VFL 2 TDSRM-+ 2 001. 1l 07H tB 07J K BDM- 2 001 18 08H 1B 08S TTYEN- 2 001 1B 09H 1 09K MDSR M+ 2 00 1 LB 07U lB 07V RDENB- 2 CO1 1R 09U 1iB 09V MDS XM+ 2 00-;3 1A 09J IA -N TTYEN- 2 003 lB 08K 1B 08S OSENB- 2 004 1B 09E 1R 09N GTDOSR- 2 00'5 18 07D LB 07R KBDM+ 2 009 IA 05E 1A 09L DSENB- 2 010 1A 08H 18 080 TTYEN- 2 C 11 1A 09K 1 B O9J T'TYKM+ 2 011 1_ A 08L 1B 08L TPM- 2 014 LA 09R tB 08U1 POM+ 2 01 5 1A 10K 1B 08R 49 WIRES @.L10 $4.90, @.15 $7.35 CARDS PUNCHED................ 0 NUMBER- OF BUSS STRIPS....... 0 NUMBER OF WRAPS......... 4Q TOTAL LENGTH OF WIRE.. * 19

-19MODULE INVENTORY.. PANEL I COST EIAR 1 17 7.00 9R17O 1 24. 00 R1 l 2 28.00 W021OMJ -1 4.50 W050 1 13*00 W602 1 40. 00 cosr OF MO"DUtLES FOR TH-S PANEL. $. s 126.50

Unclassified Security Classification DOCUMENT CONTROL DATA- ROM (Security classification of title, body of abstract and indexing annotation must be entered when the overall report is classified) 1. ORIGINATING ACTIVITY (Corporate author).2a. REPORT SECURITY C L.ASIFICATION Unclassified THE UNIVERSITY OF MICHIGAN CONCOMP PROJECT2 b GROUP 3. REPORT TITLE PDP-8 TO 103A DATAPHONE AND/OR ONLINE TELETYPE INTERFACE 4. DESCRIPTIVE NOTES (Type of report and inclusive dates) Memorandum 5. AUTHOR(S) (Last name, first name, initial) K.E. Burkhalter, Jr. 6. REPORT DATE 7'. TOTAL NO. OF PAGES 7b. NO. OF REFI April 1968 20 8a. CONTRACT OR GRANT NO. 9a., ORIGINATORS REPORT NUMBER(S) DA-49-083 OSA-3050 Memorandum 16 b. PROJECT NO. c. |9b. OTHER REPORT Ni(S) (Any othert nunbero Utht may be assigned this report) 10. A V A IL ABILITY/LIMITATION NOTICES Qualified requesters may obtain copies of this report from DDC. 1. SUPPLEMENTARY NOTES 12. SPONSORING MILITARY ACTIVITY Advanced Research Projects Aqency 13. ABSTRACT DD,JN?4 1473 Unclassified Security Classification

Security Classification 14, LINK A LINK B LINK C KEY WORDS ROLE WT ROLE WT ROLE WT INSTRUCTIONS 1. ORIGINATING ACTIVITY: Enter the name and address imposed by security classification, using standard statements of the contractor, subcontractor, grantee, Department of De- such as: fense activity or other organization (corporate author) issuing (1) "Qualified requesters may obtain copies of this the report. report from DDC." 2a. REPORT SECU[ITY CLASSIFICATION: Enter the overall security classification of the report. Indicate whether report by DDC, is not authorized." "Restricted Data" is included. Marking is to be in accordance with appropriate security regulations. (3) "U. S. Government agencies may obtain copies of this report directly from DDC. Other qualified DDC 2b. GROUP: Automatic downgrading is specified in DoD Di- users shall request through rective 5200.10 and Armed Forces Industrial Manual. Enter the group number. Also, when applicable, show that optional, markings have been used for Group 3 and Group 4 as author- (4) "U. S. military agencies may obtain copies of this report directly from DDC Other qualified users 3. REPORT TITLE: Enter the complete report title in all shall request through capital letters. Titles in all cases should be unclassified.,, If a meaningful title cannot be selected without classification, show title classification in all capitals in parenthesis (5) "All distribution of this report is controlled. Qualimmediately following the title. ified DDC users shall request through 4. DESCRIPTIVE NOTESD If appropriate, enter the type of _,, report, e.g., interim, progress, summary, annual, or final. If the report has been furnished to the Office of Technical Give the inclusive dates when a specific reporting period is Services, Department of Commerce, for sale to the public, indicovered. cate this fact and enter the price, if known. 5. AUTHOR(S): Enter the name(s) of author(s) as shown on 11. SUPPLEMENTARY NOTES: Use for additional explanaor in the report. Enter last name, first name, middle initial. tory notes. If military, show rank and branch of service. The name of the principal author is an absolute minimum requirement. 12. SPONSORING MILITARY ACTIVITY: Enter the name of the departmental project office or laboratory sponsoring (pay6. REPORT DATE. Enter the date of the report as day, ing for) the research and development. Include address. month, year; or month, year. If more than one date appears on the report, use date of publication. 13. ABSTRACT: Enter an abstract giving a brief and factual summary of the document indicative of the report, even though 7a. TOTAL NUMBER OF PAGES: The total page count it may also appear elsewhere in the body of the technical reshould follow normal pagination procedures, i.e., enter the port. If additional space is required, a continuation sheet shall number of pages containing information. be attached. 76. NUMBER OF REFERENCES: Enter the total number of It is highly desirable that the abstract of classified reports references cited in the report. be unclassified. Each paragraph of the abstract shall end with 8a. CONTRACT OR GRANT NUMBER: If appropriate, enter an indication of the military security classification of the inthe applicable number of the contract or grant under which formation in the paragraph, represented as (TS), (S), (C), or (U). the report was written. There is no limitation cn the length of the abstract. How8b, Sc, & 8d. PROJECT NUMBER: Enter the appropriate ever, the suggested length is from 150 to 225 words. military department identification, such as project number, 14. KEY WORDS: Key words are technically meaningful terms subproject number, system numbers, task number, etc. or short phrases that characterize a report and may be used as 9a. ORIGINATOR'S REPORT NUMBER(S): Enter the offi- index entries for cataloging the report. Key words must be cial report number by which the document will be identified selected so that no security classification is required. Identiand controlled by the originating activity. This number must fiers, such as equipment model designation, trade name, military be unique to this report. project code name, geographic location, may be used as key 9b. OTHER REPORT NUMBER(S): If the report has been words but will be followed by an indication of technical conassigned any other report numbers (either by the originator text. The assignment of links, rules, and weights is optional. or by the sponsor), also enter this number(s). 10. AVAILABILITY/LIMITATION NOTICES: Enter any limitations on further dissemination of the report, other than those GPO 886-551 Security Classification

o3 901 o2