Source Code

These source-code files were obtained by digitally photographing the Colossus 237 program listing from the private collection of original AGC developer Fred Martin, and then modifying pre-existing Colossus 249 (Apollo 9) source files to incorporate changes. Note that the page images presented online are of reduced quality, and that additional images are available. Report any conversion errors or legibility problems in page images to info@sandroid.org. Notations on the program listing read, in part:

	GAP: ASSEMBLE REVISION 237 OF AGC PROGRAM COLOSSUS 
	BY NASA 2021111-031  1:17 AUG. 24, 1968

046143,000002:                                                                                                 #  Copyright:     Public domain.
046144,000003:                                                                                                 #  Filename:      INTER-BANK_COMMUNICATION.agc
046145,000004:                                                                                                 #  Purpose:       Part of the source code for Colossus build 237.  
046146,000005:                                                                                                 #                 This is for the Command Module's (CM) Apollo Guidance
046147,000006:                                                                                                 #                 Computer (AGC), we believe for Apollo 8.
046148,000007:                                                                                                 #  Assembler:     yaYUL
046149,000008:                                                                                                 #  Contact:       Onno Hommes <ohommes@alumni.cmu.edu>
046150,000009:                                                                                                 #  Website:       www.ibiblio.org/apollo/index.html
046151,000010:                                                                                                 #  Page scans:    www.ibiblio.org/apollo/ScansForConversion/Colossus237/
046152,000011:                                                                                                 #  Mod history:   2010-05-22 OH   Adapted from corresponding Colossus 249 file.
046153,000012:                                                                                                 #                 2010-12-04 JL   Remove Colossus 249 header comments. Change to double-has page numbers.
046154,000013:                                                                                                 #                 2011-02-07 JL   Minor fixes.
046155,000014: 
046156,000015:                                                                                                 # # Page 1070
046157,000016:                                                                                                 #            THE FOLLOWING ROUTINE CAN BE USED TO CALL A SUBROUTINE IN ANOTHER BANK. IN THE BANKCALL VERSION, THE
046158,000017:                                                                                                 #  CADR OF THE SUBROUTINE IMMEDIATELY FOLLOWS THE  TC BANKCALL  INSTRUCTION, WITH C(A) AND C(L) PRESERVED.
046159,000018: 
046160,000019:    4555                                          BLOCK    02                                    
046161,000020:    4555                                          COUNT    02/BANK                               
046162,000021: 
046163,000022:    4555           52134        BANKCALL          DXCH     BUF2                                  #  SAVE INCOMING A,L.
046164,000023:    4556           50002                          INDEX    Q                                     #  PICK UP CADR.
046165,000024:    4557           30000                          CA       0                                     
046166,000025:    4560           24002                          INCR     Q                                     #  SO WE RETURN TO THE LOC. AFTER THE CADR.
046167,000026: 
046168,000027:                                                                                                 #            SWCALL IS IDENTICAL TO BANKCALL, EXCEPT THAT THE CADR ARRIVES IN A.
046169,000028: 
046170,000029:    4561           54001        SWCALL            TS       L                                     
046171,000030:    4562           22004                          LXCH     FBANK                                 #  SWITCH BANKS, SAVING RETURN.
046172,000031:    4563           74747                          MASK     LOW10                                 #  GET SUB-ADDRESS OF CADR.
046173,000032:    4564           56002                          XCH      Q                                     #  A,L NOW CONTAINS DP RETURN.
046174,000033:    4565           52134                          DXCH     BUF2                                  #  RESTORING INPUTS IF THIS IS A BANKCALL.
046175,000034:    4566           50002                          INDEX    Q                                     
046176,000035:    4567           02000                          TC       10000                                 #  SETTING Q TO SWRETURN.
046177,000036: 
046178,000037:    4570           56134        SWRETURN          XCH      BUF2       +1                         #  COMES HERE TO RETURN TO CALLER. C(A,L)
046179,000038:    4571           56004                          XCH      FBANK                                 #  ARE PRESERVED FOR RETURN.
046180,000039:    4572           56134                          XCH      BUF2       +1                         
046181,000040:    4573           00133                          TC       BUF2                                  
046182,000041: 
046183,000042: 
046184,000043:                                                                                                 #            THE FOLLOWING ROUTINE CAN BE USED AS A UNILATERAL JUMP WITH C(A,L) PRESERVED AND THE CADR IMMEDIATELY
046185,000044:                                                                                                 #  FOLLOWING THE TC POSTJUMP INSTRUCTION.
046186,000045: 
046187,000046:    4574           56002        POSTJUMP          XCH      Q                                     #  SAVE INCOMING C(A).
046188,000047:    4575           50000                          INDEX    A                                     #  GET CADR.
046189,000048:    4576           30000                          CA       0                                     
046190,000049: 
046191,000050:                                                                                                 #            BANKJUMP IS THE SAME AS POSTJUMP, EXCEPT THAT THE CADR ARRIVES IN A.
046192,000051: 
046193,000052:    4577           54004        BANKJUMP          TS       FBANK                                 
046194,000053:    4600           74747                          MASK     LOW10                                 
046195,000054:    4601           56002                          XCH      Q                                     #  RESTORING INPUT C(A) IF THIS WAS A
046196,000055:    4602           50002        Q+10000           INDEX    Q                                     #  POSTJUMP.
046197,000056:    4603           12000        PRIO12            TCF      10000                                 #  PRIO12 = TCF   10000 = 12000
046198,000057: 
046199,000058:                                                                                                 # # Page 1071
046200,000059:                                                                                                 #            THE FOLLOWING ROUTINE GETS THE RETURN CADR SAVED BY SWCALL OR BANKCALL AND LEAVES IT IN A.
046201,000060: 
046202,000061:    4604           34747        MAKECADR          CAF      LOW10                                 
046203,000062:    4605           70133                          MASK     BUF2                                  
046204,000063:    4606           60134                          AD       BUF2       +1                         
046205,000064:    4607           00002                          TC       Q                                     
046206,000065: 
046207,000066: 
046208,000067:    4610           54135        SUPDACAL          TS       MPTEMP                                
046209,000068:    4611           56004                          XCH      FBANK                                 #  SET FBANK FOR DATA.
046210,000069:    4612           00006                          EXTEND                                         
046211,000070:    4613           04007                          ROR      SUPERBNK                              #  SAVE FBANK IN BITS 15-11, AND
046212,000071:    4614           56135                          XCH      MPTEMP                                #   SUPERBANK IN BITS 7-5.
046213,000072:    4615           74747                          MASK     LOW10                                 
046214,000073:    4616           56001                          XCH      L                                     #  SAVE REL. ADR. IN BANK, FETCH SUPERBITS.
046215,000074:    4617           00004                          INHINT                                         #  BECAUSE RUPT DOES NOT SAVE SUPERBANK.
046216,000075:    4620           00006                          EXTEND                                         
046217,000076:    4621           01007                          WRITE    SUPERBNK                              #  SET SUPERBANK FOR DATA.
046218,000077:    4622           50001                          INDEX    L                                     
046219,000078:    4623           32000                          CA       10000                                 #  PINBALL (FIX MEM DISP) PREVENTS DCA HERE
046220,000079:    4624           56135                          XCH      MPTEMP                                #  SAVE 1ST WD, FETCH OLD FBANK AND SBANK.
046221,000080:    4625           00006                          EXTEND                                         
046222,000081:    4626           01007                          WRITE    SUPERBNK                              #  RESTORE SUPERBANK.
046223,000082:    4627           00003                          RELINT                                         
046224,000083:    4630           54004                          TS       FBANK                                 #  RESTORE FBANK.
046225,000084:    4631           30135                          CA       MPTEMP                                #  RECOVER FIRST WORD OF DATA.
046226,000085:    4632           00002                          RETURN                                         #  24 WDS. DATACALL 516 MU, SUPDACAL 432 MU
046227,000086: 
046228,000087:                                                                                                 # # Page 1072
046229,000088:                                                                                                 #            THE FOLLOWING ROUTINES ARE IDENTICAL TO BANKCALL AND SWCALL EXCEPT THAT THEY ARE USED IN INTERRUPT.
046230,000089: 
046231,000090:    4633           52073        IBNKCALL          DXCH     RUPTREG3                              #  USES RUPTREG3,4 FOR DP RETURN ADDRESS.
046232,000091:    4634           50002                          INDEX    Q                                     
046233,000092:    4635           30000                          CAF      0                                     
046234,000093:    4636           24002                          INCR     Q                                     
046235,000094: 
046236,000095:    4637           54001        ISWCALL           TS       L                                     
046237,000096:    4640           22004                          LXCH     FBANK                                 
046238,000097:    4641           74747                          MASK     LOW10                                 
046239,000098:    4642           56002                          XCH      Q                                     
046240,000099:    4643           52073                          DXCH     RUPTREG3                              
046241,000100:    4644           50002                          INDEX    Q                                     
046242,000101:    4645           02000                          TC       10000                                 
046243,000102: 
046244,000103:    4646           56073        ISWRETRN          XCH      RUPTREG4                              
046245,000104:    4647           56004                          XCH      FBANK                                 
046246,000105:    4650           56073                          XCH      RUPTREG4                              
046247,000106:    4651           00072                          TC       RUPTREG3                              
046248,000107: 
046249,000108:                                                                                                 #  2. USPRCADR ACCESSES INTERPRETIVE CODING IN OTHER THAN THE USER'S FBANK. THE CALLING SEQUENCE IS AS FOLLOWS:
046250,000109: 
046251,000110:                                                                                                 #                                           L        TC     USPRCADR
046252,000111:                                                                                                 #                                           L+1      CADR   INTPRETX        INTPRETX IS THE INTERPRETIVE CODING
046253,000112:                                                                                                 #                                                                           RETURN IS TO L+2
046254,000113: 
046255,000114:    4652           54164        USPRCADR          TS       LOC                                   #  SAVE A
046256,000115:    4653           34703                          CA       BIT8                                  
046257,000116:    4654           54023                          TS       EDOP                                  #  EXIT INSTRUCTION TO EDOP
046258,000117:    4655           30006                          CA       BBANK                                 
046259,000118:    4656           54165                          TS       BANKSET                               #  USER'S BBANK TO BANKSET
046260,000119:    4657           50002                          INDEX    Q                                     
046261,000120:    4660           30000                          CA       0                                     
046262,000121:    4661           54004                          TS       FBANK                                 #  INTERPRETIVE BANK TO FBANK
046263,000122:    4662           74747                          MASK     LOW10                                 #  YIELDS INTERPRETIVE RELATIVE ADDRESS
046264,000123:    4663           56002                          XCH      Q                                     #  INTERPRETIVE ADDRESS TO Q, FETCHING L+1
046265,000124:    4664           56164                          XCH      LOC                                   #  L+1 TO LOC, RETRIEVING ORIGINAL A
046266,000125:    4665           14602                          TCF      Q+10000                               
046267,000126: 
046268,000127:                                                                                                 # # Page 1073
046269,000128:                                                                                                 #  THERE ARE FOUR POSSIBLE SETTINGS FOR CHANNEL 07. (CHANNEL 07 CONTAINS THE SUPERBANK SETTING.)
046270,000129:                                                                                                 #                                            PSEUDO-FIXED     OCTAL PSEUDO
046271,000130:                                                                                                 #  SUPERBANK     SETTING     S-REG. VALUE    BANK NUMBERS     ADDRESSES
046272,000131:                                                                                                 #  ----------    -------     ------------     ------------     ------------
046273,000132: 
046274,000133:                                                                                                 #  SUPERBANK 3     0XX       2000 - 3777        30 - 37       70000 - 107777   (WHERE XX CAN BE ANYTHING AND
046275,000134:                                                                                                 #                                                                              WILL USUALLY BE SEEN AS 11)
046276,000135:                                                                                                 #  SUPERBANK 4     100       2000 - 3777        40 - 47       110000 - 127777  (AS FAR AS IT CAN BE SEEN,
046277,000136:                                                                                                 #                                                                              ONLY BANKS 40-43 WILL EVER BE
046278,000137:                                                                                                 #                                                                              AND ARE PRESENTLY AVAILABLE)
046279,000138:                                                                                                 #  SUPERBANK 5     101       2000 - 3777        50 - 57       130000 - 147777  (PRESENTLY NOT AVAILABLE TO
046280,000139:                                                                                                 #                                                                              THE USER)
046281,000140:                                                                                                 #  SUPERBANK 6     110       2000 - 3777        60 - 67       150000 - 167777  (PRESENTLY NOT AVAILABLE TO
046282,000141:                                                                                                 #                                                                              THE USER)
046283,000142:                                                                                                 #  ***  THIS ROUTINE MAYBE CALLED BY ANY PROGRAM LOCATED IN BANKS 00 - 27.  I.E., NO PROGRAM LIVING IN ANY
046284,000143:                                                                                                 #  SUPERBANK SHOULD USE SUPERSW.  ***
046285,000144: 
046286,000145:                                                                                                 #  SUPERSW MAYBE CALLED IN THIS FASHION:
046287,000146: 
046288,000147:                                                                                                 #           CAF    ABBCON          WHERE  --  ABBCON   BBCON  SOMETHIN --
046289,000148:                                                                                                 #           TCR    SUPERSW         (THE SUPERBNK BITS ARE IN THE BBCON)
046290,000149:                                                                                                 #           ...      ...
046291,000150:                                                                                                 #            .        .
046292,000151:                                                                                                 #            .        .
046293,000152: 
046294,000153:                                                                                                 #  OR IN THIS FASHION :
046295,000154: 
046296,000155:                                                                                                 #           CAF    SUPERSET        WHERE SUPERSET IS ONE OF THE FOUR AVAILABLE
046297,000156:                                                                                                 #           TCR    SUPERSW         SUPERBANK BIT CONSTANTS:
046298,000157:                                                                                                 #           ...      ...                                   SUPER011 OCTAL  60
046299,000158:                                                                                                 #            .        .                                    SUPER100 OCTAL 100
046300,000159:                                                                                                 #            .        .                                    SUPER101 OCTAL 120
046301,000160:                                                                                                 #                                                          SUPER110 OCTAL 140
046302,000161: 
046303,000162:    4666           00006        SUPERSW           EXTEND                                         
046304,000163:    4667           01007                          WRITE    SUPERBNK                              #  WRITE BITS 7-6-5 OF THE ACCUMULATOR INTO
046305,000164:                                                                                                 #  CHANNEL 07
046306,000165:    4670           00002                          TC       Q                                     #  TC TO INSTRUCTION FOLLOWING
046307,000166:                                                                                                 #    TC  SUPERSW

End of include-file INTER-BANK_COMMUNICATION.agc.  Parent file is MAIN.agc