Apollo-11/Comanche055

Comanche055

This source code has been transcribed or otherwise adapted from digitized images of a hardcopy from the MIT Museum. The digitization was performed by Paul Fjeld, and arranged for by Deborah Douglas of the Museum. Many thanks to both.

The images (with suitable reduction in storage size and consequent reduction in image quality as well) are available online at www.ibiblio.org/apollo. If for some reason you find that the images are illegible, contact me at info@sandroid.org about getting access to the (much) higher-quality images which Paul actually created.

Notations on the hardcopy document read, in part:

Assemble revision 055 of AGC program Comanche by NASA
2021113-051.  10:28 APR. 1, 1969

This AGC program shall also be referred to as
		Colossus 2A

Background

For organizatinal purposes RSB split the huge monolithic source code into smaller, more manageable chunks--i.e., into individual source files. Those files are rejoined as "includes". The code chunks correspond to natural divisions into sub-programs. In fact, these divisions are more-or-less specified by the source code itself. Refer to the "SUBROUTINE CALLS" at the very beginning of ASSEMBLY_AND_OPERATION_INFORMATION.agc.

It may be reasonably asked why tens of thousands of lines of source are joined by means of inclusion, rather than simply assembling the source files individually and then linking them to form the executable. The answer is that the original development team had no linker. The builds were monolithic just like this.

There was a big emphasis on reusability of the code in the original project, apparently, but this reusability took the form of inserting your deck of punch-cards at the appropriate position in somebody else's deck of punch-cards. (Actually, I think the card-decks were turned into tape libraries, and the modules were mixed-and-matched from the tape libraries, but the principle is the same.) So, indeed, the method of file-inclusion is a very fair representation of the methods used in the original development...with the improvement, of course, that you no longer have to worry about dropping the card deck. On the other hand, I (RSB) wasn't there at the time, so I may have no idea what I'm talking about.

Finally, note that the original Apollo AGC assembler (called YUL) is no longer available (as far as I can tell). Actually, it had already been replaced by another assembler (called GAP) by the time of Apollo 11, but GAP isn't available either. The replacement assembler yaYUL accepts a slightly different format for the source code from what YUL or GAP accepted, so the source code has been targeted for assembly with yaYUL.

What follows is simply a bunch of file-includes for the individual code chunks. The page numbers have been marked to make proof-reading easier. The page images also contain a lot of interesting tables (cross-referenced to page numbers) created by GAP, but not duplicated by yaYUL, so it's still valuable even if the source-files listed below are in hand.

Source Code Index

INFORMATION

Source File	Page Number
CONTRACT_AND_APPROVALS.agc	1
ASSEMBLY_AND_OPERATION_INFORMATION.agc	2-26
TAGS_FOR_RELATIVE_SETLOC.agc	27-35

COMERASE

Source File	Page Number
ERASABLE_ASSIGNMENTS.agc	37-130

COMAID

Source File	Page Number
INTERRUPT_LEAD_INS.agc	131-132
T4RUPT_PROGRAM.agc	133-169
DOWNLINK_LISTS.agc	170-180
FRESH_START_AND_RESTART.agc	181-210
RESTART_TABLES.agc	211-221
SXTMARK.agc	222-235
EXTENDED_VERBS.agc	236-267
PINBALL_NOUN_TABLES.agc	268-284
CSM_GEOMETRY.agc	285-296
IMU_COMPENSATION_PACKAGE.agc	297-306
PINBALL_GAME_BUTTONS_AND_LIGHTS.agc	307-389
R60_62.agc	390-398
ANGLFIND.agc	399-411
GIMBAL_LOCK_AVOIDANCE.agc	412-413
KALCMANU_STEERING.agc	414-419
SYSTEM_TEST_STANDARD_LEAD_INS.agc	420-422
IMU_CALIBRATION_AND_ALIGNMENT.agc	423-455

COMEKISS

Source File	Page Number
GROUND_TRACKING_DETERMINATION_PROGRAM.agc	456-459
P34-35_P74-75.agc	460-504
R31.agc	505-510
P76.agc	511-513
R30.agc	514-524
STABLE_ORBIT.agc	525-532

TROUBLE

Source File	Page Number
P11.agc	533-550
TPI_SEARCH.agc	551-561
P20-P25.agc	562-634
P30-P37.agc	635-648
P32-P33_P72-P73.agc	649-683
P40-P47.agc	684-736
P51-P53.agc	737-784
LUNAR_AND_SOLAR_EPHEMERIDES_SUBROUTINES.agc	785-788
P61-P67.agc	789-818
SERVICER207.agc	819-836
ENTRY_LEXICON.agc	837-843
REENTRY_CONTROL.agc	844-882
CM_BODY_ATTITUDE.agc	883-889
P37_P70.agc	890-933
S-BAND_ANTENNA_FOR_CM.agc	934-935
LUNAR_LANDMARK_SELECTION_FOR_CM.agc	936

TVCDAPS

Source File	Page Number
TVCINITIALIZE.agc	937-944
TVCEXECUTIVE.agc	945-950
TVCMASSPROP.agc	951-955
TVCRESTARTS.agc	956-960
TVCDAPS.agc	961-978
TVCSTROKETEST.agc	979-983
TVCROLLDAP.agc	984-998
MYSUBS.agc	999-1001
RCS-CSM_DIGITAL_AUTOPILOT.agc	1002-1024
AUTOMATIC_MANEUVERS.agc	1025-1036
RCS-CSM_DAP_EXECUTIVE_PROGRAMS.agc	1037-1038
JET_SELECTION_LOGIC.agc	1039-1062
CM_ENTRY_DIGITAL_AUTOPILOT.agc	1063-1092

CHIEFTAN

Source File	Page Number
DOWN-TELEMETRY_PROGRAM.agc	1093-1102
INTER-BANK_COMMUNICATION.agc	1103-1106
INTERPRETER.agc	1107-1199
FIXED_FIXED_CONSTANT_POOL.agc	1200-1204
INTERPRETIVE_CONSTANTS.agc	1205-1206
SINGLE_PRECISION_SUBROUTINES.agc	1207
EXECUTIVE.agc	1208-1220
WAITLIST.agc	1221-1235
LATITUDE_LONGITUDE_SUBROUTINES.agc	1236-1242
PLANETARY_INERTIAL_ORIENTATION.agc	1243-1251
MEASUREMENT_INCORPORATION.agc	1252-1261
CONIC_SUBROUTINES.agc	1262-1308
INTEGRATION_INITIALIZATION.agc	1309-1333
ORBITAL_INTEGRATION.agc	1334-1354
INFLIGHT_ALIGNMENT_ROUTINES.agc	1355-1364
POWERED_FLIGHT_SUBROUTINES.agc	1365-1372
TIME_OF_FREE_FALL.agc	1373-1388
STAR_TABLES.agc	1389-1393
AGC_BLOCK_TWO_SELF-CHECK.agc	1394-1403
PHASE_TABLE_MAINTENANCE.agc	1404-1413
RESTARTS_ROUTINE.agc	1414-1419
IMU_MODE_SWITCHING_ROUTINES.agc	1420-1448
KEYRUPT_UPRUPT.agc	1449-1451
DISPLAY_INTERFACE_ROUTINES.agc	1452-1484
SERVICE_ROUTINES.agc	1485-1492
ALARM_AND_ABORT.agc	1493-1496
UPDATE_PROGRAM.agc	1497-1507
RT8_OP_CODES.agc	1508-1516

MISCELLANEOUS

Source File	Page Number
GAP-generated tables	1517-1751