Source Code
|
These source-code files are part of a reconstructed copy of Sundial E, the
final release of the Block II Command Module (CM) Apollo Guidance Computer
(AGC) system test software.
They have been created via disassembly of binary dumps of original core rope memory modules, part numbers 2003053-121, 2003053-151, and 2003972-211, belonging to the MIT Museum. Since only binary dumps (rather than listings) of Sundial are available as source material, all comments and labels are approximate. They have been taken from other AGC programs where possible, or, in some places, written from scratch to match what we believe would have been in the original listing. |
004192,000002: ## Copyright: Public domain.
004193,000003: ## Filename: SINGLE_PRECISION_SUBROUTINES.agc
004194,000004: ## Purpose: A section of Sundial E.
004195,000005: ## It is part of the reconstructed source code for the final
004196,000006: ## release of the Block II Command Module system test software. No
004197,000007: ## original listings of this program are available; instead, this
004198,000008: ## file was created via disassembly of dumps of Sundial core rope
004199,000009: ## modules and comparison with other AGC programs.
004200,000010: ## Assembler: yaYUL
004201,000011: ## Contact: Ron Burkey <info@sandroid.org>.
004202,000012: ## Website: www.ibiblio.org/apollo/index.html
004203,000013: ## Mod history: 2023-06-22 MAS Created from Aurora 12.
004204,000014: ## 2023-06-30 MAS Updated for Sundial E.
004205,000015:
004206,000016:
004207,000017: 4151 SETLOC ENDIBNKF
004208,000018:
004209,000019: # SINGLE PRECISION SINE AND COSINE
004210,000020:
004211,000021: 4151 67635 SPCOS AD HALF # ARGUMENTS SCALED AT PI
004212,000022: 4152 55106 SPSIN TS TEMK
004213,000023: 4153 14155 TCF SPT
004214,000024: 4154 41106 CS TEMK
004215,000025: 4155 60000 SPT DOUBLE
004216,000026: 4156 55106 TS TEMK
004217,000027: 4157 14172 TCF POLLEY
004218,000028: 4160 57106 XCH TEMK
004219,000029: 4161 51106 INDEX TEMK
004220,000030: 4162 67633 AD LIMITS
004221,000031: 4163 40000 COM
004222,000032: 4164 61106 AD TEMK
004223,000033: 4165 55106 TS TEMK
004224,000034: 4166 14172 TCF POLLEY
004225,000035: 4167 50000 INDEX A
004226,000036: 4170 37634 CA LIMITS +1
004227,000037: 4171 00002 TC Q
004228,000038: 4172 00006 POLLEY EXTEND
004229,000039: 4173 71106 MP TEMK
004230,000040: 4174 55107 TS SQ
004231,000041: 4175 00006 EXTEND
004232,000042: 4176 74210 MP C5/2
004233,000043: 4177 64207 AD C3/2
004234,000044: 4200 00006 EXTEND
004235,000045: 4201 71107 MP SQ
004236,000046: 4202 64206 AD C1/2
004237,000047: 4203 00006 EXTEND
004238,000048: 4204 71106 MP TEMK
004239,000049: 4205 00002 TC Q # RESULT SCALED AT 1
004240,000050: 4206 31103 C1/2 DEC .7853134
004241,000051: 4207 65552 C3/2 DEC -.3216146
004242,000052: 4210 01124 C5/2 DEC .0363551
004243,000053: # ENTER WITH ARGUMENT IN A, EXIT WITH ROOT IN A. IF GIVEN A NEGATIVE ARGUMENT, THE RETURN SKIPS WITH CCS RESULT.
004244,000054: # MINUS ZERO RETURNS LIKE PLUS ZERO.
004245,000055: # MAXIMUM ERROR IN ANSWER IS NO GREATER THAN 2 BITS.
004246,000056: # INTERRUPT PROGRAMS USING SPROOT MUST SAVE AND RESTORE SR.
004247,000057:
004248,000058:
004249,000059:
004250,000060: 4211 55110 SPROOT TS SQRARG # ENTER WITH C(A) = Y
004251,000061: 4212 10000 CCS A
004252,000062: 4213 14217 TCF POSARG # IF PNZ, CONTINUE
004253,000063: 4214 00002 TC Q # RETURN WITH 0 FOR +0
004254,000064: 4215 24002 INCR Q
004255,000065: 4216 00002 TC Q # RETURN WITH 0 FOR -0
004256,000066:
004257,000067: 4217 00006 POSARG EXTEND
004258,000068: 4220 23107 QXCH ROOTRET # WILL BE CALLING SPROOT1
004259,000069: 4221 64275 AD 63/64+1 # B(A) = Y - 1
004260,000070: 4222 54000 OVSK
004261,000071: 4223 14264 TCF SPROOT2
004262,000072: 4224 57110 XCH SQRARG # ARG JUGGLING
004263,000073:
004264,000074: 4225 55110 SPROOT3 TS SQRARG
004265,000075: 4226 54021 TS SR # C(A) = Y
004266,000076: 4227 56021 XCH SR # (LOSE 1 BIT)
004267,000077: 4230 55106 TS HALFY # HALFY = Y/2
004268,000078: 4231 64273 AD -1/8 # FORM Y/2 - 1/8
004269,000079: 4232 10000 CCS A # TEST FOR FIRST GUESS
004270,000080: 4233 64274 AD 5/8+1 # Y .G. 1/4, X = Y/2 + 1/2
004271,000081: 4234 04241 TC HIGUESS # +0 IMPOSSIBLE FROM ADDITION
004272,000082: 4235 14236 NOOP # Y .LE. 1/4, X/2 = Y + 1/16
004273,000083: 4236 37640 CAF BIT11 # 1/16
004274,000084: 4237 61110 AD SQRARG # SQRARG = Y
004275,000085: 4240 60000 DOUBLE # X FROM X/2
004276,000086: 4241 04254 HIGUESS TC SPROOT1
004277,000087: 4242 04254 TC SPROOT1 # ITERATE TWICE
004278,000088: 4243 57107 XCH ROOTRET # SAVE ANSWER AND GET Q
004279,000089: 4244 10000 CCS A
004280,000090: 4245 57107 XCH ROOTRET # NO SHIFT NEEDED
004281,000091: 4246 04252 TC ROOTBCK
004282,000092: 4247 57107 XCH ROOTRET # Q NEG, SHIFT RIGHT THREE
004283,000093: 4250 00006 EXTEND
004284,000094: 4251 77637 MP BIT12 # EXP -3
004285,000095: 4252 51107 ROOTBCK INDEX ROOTRET # ROOTRET = Q - 1
004286,000096: 4253 00001 TC 1 # RETURN, C(A) = SQRT(Y)
004287,000097:
004288,000098: 4254 56021 SPROOT1 XCH SR # SR = X/2
004289,000099: 4255 41106 CS HALFY # NEWTON ITER X = X/2 + (Y/2 / X/2) / 2
004290,000100: 4256 00006 EXTEND
004291,000101: 4257 10021 DV SR # C(SR) = X/2 DV DOES NOT EDIT
004292,000102: 4260 56021 XCH SR
004293,000103: 4261 00006 EXTEND
004294,000104: 4262 60021 SU SR
004295,000105: 4263 00002 TC Q # C(A) = X (NEXT)
004296,000106:
004297,000107: 4264 41107 SPROOT2 CS ROOTRET # SET RETURN Q NEG, AS FLAG
004298,000108: 4265 55107 TS ROOTRET
004299,000109: 4266 37644 CAF BIT7 # SHIFT FOR SIGNIFCANCE
004300,000110: 4267 00006 EXTEND
004301,000111: 4270 71110 MP SQRARG
004302,000112: 4271 30001 CA L # B(A) = 0
004303,000113: 4272 04225 TC SPROOT3
004304,000114:
004305,000115: 4273 73777 -1/8 OCTAL 73777
004306,000116: 4274 24001 5/8+1 OCTAL 24001
004307,000117: 4275 37401 63/64+1 OCTAL 37401
004308,000118:
004309,000119:
004310,000120:
004311,000121: 4276 ENDSUBSF EQUALS
End of include-file SINGLE_PRECISION_SUBROUTINES.agc. Parent file is MAIN.agc