Source Code

These source-code files derive from a printout of Luminary 210 (Apollo 15-17 Lunar Module guidance computer program), from the personal library of original AGC developer Don Eyles, digitally photographed at archive.org, financially sponsored by Jim Lawton, and transcribed to source code by a team of volunteers. This colorized, syntax-highlighted form was created by assembling that transcribed source code. Note that the full page images are available on the Virtual AGC project page at archive.org, while reduced-size images are presented at the VirtualAGC project website. Report or fix any transcription errors at the Virtual AGC project code repository.

Notations on the program listing read, in part:

	GAP: ASSEMBLE REVISION 210 OF AGC PROGRAM LUMINARY 
	BY NASA 2021112-161 17:11 MAR. 19,1971
Note that the date is the date of the printout, not the date of the program revision.

039554,000002:                                                                                                  ## Copyright:   Public domain.
039555,000003:                                                                                                  ## Filename:    LANDING_ANALOG_DISPLAYS.agc
039556,000004:                                                                                                  ## Purpose:     A section of Luminary revision 210.
039557,000005:                                                                                                  ##              It is part of the source code for the Lunar Module's (LM)
039558,000006:                                                                                                  ##              Apollo Guidance Computer (AGC) for Apollo 15-17.
039559,000007:                                                                                                  ##              This file is intended to be a faithful transcription, except
039560,000008:                                                                                                  ##              that the code format has been changed to conform to the
039561,000009:                                                                                                  ##              requirements of the yaYUL assembler rather than the
039562,000010:                                                                                                  ##              original YUL assembler.
039563,000011:                                                                                                  ## Reference:   pp. 895-904
039564,000012:                                                                                                  ## Assembler:   yaYUL
039565,000013:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
039566,000014:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
039567,000015:                                                                                                  ## Mod history: 2016-11-17 JL   Created from Luminary131 version.
039568,000016:                                                                                                  ##              2016-11-27 HG   Transcribed
039569,000017:                                                                                                  ##              2016-12-12 HG   Fix operannd modifier none -> +4
039570,000018:                                                                                                  ##              2016-12-25 RSB  Comment-text proofed using ProoferComments
039571,000019:                                                                                                  ##                              and corrected errors found.
039572,000020:                                                                                                  ##              2017-08-19 MAS  Fixed a typo found while transcribing Zerlina 56.
039573,000021: 

Page 895

039575,000023: 21,2170                                           BANK     21                                    
039576,000024: 21,2000                                           SETLOC   R10                                   
039577,000025: 21,2000                                           BANK                                           
039578,000026: 
039579,000027: 21,2170  E7,1777                                  EBANK=   END-E7                                
039580,000028: 21,2170                                           COUNT*   $$/R10                                
039581,000029: 
039582,000030:                                                                                                  #  ****************************************************************************************************************
039583,000031:                                                                                                  #  LANADISP:  DISPLAY INERTIAL DATA ROUTINE FOR DESCENT AND ABORTS                            THIS VERSION BY EYLES
039584,000032:                                                                                                  #  ****************************************************************************************************************
039585,000033: 
039586,000034: 21,2170           23722        LANADISP           LXCH     PIPCTR1                               #  UPDATE TBASE2 AND PIPCTR SIMULTANEOUSLY
039587,000035: 21,2171           40025                           CS       TIME1                                 
039588,000036: 21,2172           53055                           DXCH     TBASE2                                
039589,000037: 
039590,000038: 21,2173           40103                           CS       FLAGWRD7                              #  IS LANDING ANALOG DISPLAYS FLAG SET?
039591,000039: 21,2174           74732                           MASK     SWANDBIT                              
039592,000040: 21,2175           10000                           CCS      A                                     
039593,000041: 21,2176           12654                           TCF      DISPRSET   +1                         #  NO:   GO RESET
039594,000042: 
039595,000043:                                                                                                  #  ************************************************************************
039596,000044:                                                                                                  #  COMPUTE VELOCITY VECTOR
039597,000045:                                                                                                  #  ************************************************************************
039598,000046: 
039599,000047:                                                                                                  #  DO EVERYTHING POSSIBLE BEFORE READING PIPAS.
039600,000048: 
039601,000049: 21,2177           00006                           EXTEND                                         
039602,000050: 21,2200           41702                           DCS      VSURFACE                              
039603,000051: 21,2201           53721                           DXCH     VVECTX                                
039604,000052: 21,2202           00006                           EXTEND                                         
039605,000053: 21,2203           31527                           DCA      V                                     
039606,000054: 21,2204           20001                           DDOUBL                                         
039607,000055: 21,2205           20001                           DDOUBL                                         
039608,000056: 21,2206           21721                           DAS      VVECTX                                
039609,000057: 
039610,000058: 21,2207           00006                           EXTEND                                         
039611,000059: 21,2210           41704                           DCS      VSURFACE   +2                         
039612,000060: 21,2211           53723                           DXCH     VVECTY                                
039613,000061: 21,2212           00006                           EXTEND                                         
039614,000062: 21,2213           31531                           DCA      V          +2                         
039615,000063: 21,2214           20001                           DDOUBL                                         
039616,000064: 21,2215           20001                           DDOUBL                                         
039617,000065: 21,2216           21723                           DAS      VVECTY                                
039618,000066: 
039619,000067: 21,2217           00006                           EXTEND                                         
039620,000068: 21,2220           41706                           DCS      VSURFACE   +4                         
039621,000069: 21,2221           53725                           DXCH     VVECTZ                                
039622,000070: 21,2222           00006                           EXTEND                                         
039623,000071: 21,2223           31533                           DCA      V          +4                         
039624,000072: 21,2224           20001                           DDOUBL                                         
039625,000073: 

Page 896

039627,000075: 21,2225           20001                           DDOUBL                                         
039628,000076: 21,2226           21725                           DAS      VVECTZ                                
039629,000077: 
039630,000078:                                                                                                  #  COMPUTE TIME SINCE PIPTIME.
039631,000079: 
039632,000080: 21,2227           41234                           CS       PIPTIME    +1                         
039633,000081: 21,2230           60025                           AD       TIME1                                 
039634,000082: 21,2231           64727                           AD       HALF                                  
039635,000083: 21,2232           64727                           AD       HALF                                  
039636,000084: 21,2233           57717                           XCH      DT                                    #  DT SINCE PIPTIME IN UNITS 0F 2(14) CS
039637,000085: 
039638,000086:                                                                                                  #  ADD IN PIPA PULSES.
039639,000087: 
039640,000088: 21,2234           31157                           CA       PIPATMPX                              
039641,000089: 21,2235           60037                           AD       PIPAX                                 
039642,000090: 21,2236           00006                           EXTEND                                         
039643,000091: 21,2237           72000                           MP       LANAKPIP                              
039644,000092: 21,2240           21721                           DAS      VVECTX                                
039645,000093: 
039646,000094: 21,2241           31160                           CA       PIPATMPY                              
039647,000095: 21,2242           60040                           AD       PIPAY                                 
039648,000096: 21,2243           00006                           EXTEND                                         
039649,000097: 21,2244           72000                           MP       LANAKPIP                              
039650,000098: 21,2245           21723                           DAS      VVECTY                                
039651,000099: 
039652,000100: 21,2246           31161                           CA       PIPATMPZ                              
039653,000101: 21,2247           60041                           AD       PIPAZ                                 
039654,000102: 21,2250           00006                           EXTEND                                         
039655,000103: 21,2251           72000                           MP       LANAKPIP                              
039656,000104: 21,2252           21725        QUARDUMP           DAS      VVECTZ                                #  TAG IS FOR EDITS
039657,000105: 
039658,000106:                                                                                                  #  FINALLY, ADD IN CONTRIBUTIONS OF GRAVITY AND PIPA BIAS.
039659,000107: 
039660,000108: 21,2253           31676                           CA       G-VBIASX                              #  G-VBIASX IS IN UNITS OF 2(-9) M/CS/CS
039661,000109: 21,2254           00006                           EXTEND                                         
039662,000110: 21,2255           71717                           MP       DT                                    
039663,000111: 21,2256           21721                           DAS      VVECTX                                #  VVECTX IN UNITS OF 2(5) M/CS
039664,000112: 
039665,000113: 21,2257           31677                           CA       G-VBIASY                              #  G-VBIASY IS IN UNITS OF 2(-9) M/CS/CS
039666,000114: 21,2260           00006                           EXTEND                                         
039667,000115: 21,2261           71717                           MP       DT                                    
039668,000116: 21,2262           21723                           DAS      VVECTY                                #  VVECTY IN UNITS OF 2(5) M/CS
039669,000117: 
039670,000118: 21,2263           31700                           CA       G-VBIASZ                              #  G-VBIASZ IS IN UNITS OF 2(-9) M/CS/CS
039671,000119: 21,2264           00006                           EXTEND                                         
039672,000120: 21,2265           71717                           MP       DT                                    
039673,000121: 21,2266           21725                           DAS      VVECTZ                                #  VVECTZ IN UNITS OF 2(5) M/CS
039674,000122: 
039675,000123:                                                                                                  #  ************************************************************************
039676,000124:                                                                                                  #  COMPUTE ALTITUDE AND ALTITUDE-RATE
039677,000125: 

Page 897

039679,000127:                                                                                                  #  ************************************************************************
039680,000128: 21,2267           31714        ALTSTUFF           CA       RUNITX                                #  COMPUTE RADIAL VELOCITY
039681,000129: 21,2270           00006                           EXTEND                                         
039682,000130: 21,2271           71720                           MP       VVECTX                                
039683,000131: 21,2272           53727                           DXCH     ALTRATE                               
039684,000132: 21,2273           31714                           CA       RUNITX                                #  COMPUTE THE MORE SENSITIVE TERM IN DP
039685,000133: 21,2274           00006                           EXTEND                                         
039686,000134: 21,2275           71721                           MP       VVECTX     +1                         
039687,000135: 21,2276           54001                           TS       L                                     
039688,000136: 21,2277           34746                           CAF      ZERO                                  
039689,000137: 21,2300           21727                           DAS      ALTRATE                               
039690,000138: 21,2301           31715                           CA       RUNITY                                #  NOTE:  WITH NORMAL DESCENT IMU ALIGNMENT
039691,000139: 21,2302           00006                           EXTEND                                         #    THIS TERM IS ALWAYS ZERO, BUT ALTRATE
039692,000140: 21,2303           71722                           MP       VVECTY                                #    CAN BE DISPLAYED DURING ASCENT TOO
039693,000141: 21,2304           21727                           DAS      ALTRATE                               
039694,000142: 21,2305           31716                           CA       RUNITZ                                
039695,000143: 21,2306           00006                           EXTEND                                         
039696,000144: 21,2307           71724                           MP       VVECTZ                                
039697,000145: 21,2310           21727                           DAS      ALTRATE                               
039698,000146: 
039699,000147: 21,2311           31713                           CA       DALTRATE                              #  COMPENSATE FOR CHANGE IN DIRECTION OF R
039700,000148: 21,2312           00006                           EXTEND                                         
039701,000149: 21,2313           71717                           MP       DT                                    
039702,000150: 21,2314           21727                           DAS      ALTRATE                               #  ALTRATE IN UNITS OF 2(5) M/CS
039703,000151: 
039704,000152: 21,2315           00006                           EXTEND                                         
039705,000153: 21,2316           31727                           DCA      ALTRATE                               
039706,000154: 21,2317           52064                           DXCH     ALTRTEMP                              
039707,000155: 21,2320           00006                           EXTEND                                         
039708,000156: 21,2321           31712                           DCA      HDOTLAD                               
039709,000157: 21,2322           20064                           DAS      ALTRTEMP                              #  AVERAGE ALTRATE IN UNITS OF 2(4) M/CS
039710,000158: 
039711,000159:                                                                                                  #  THE FOLLOWING COMPUTATION FAILS IF DT EXCEEDS 20.47 SECONDS (UNLIKELY).
039712,000160: 
039713,000161: 21,2323           31717                           CA       DT                                    
039714,000162: 21,2324           00006                           EXTEND                                         
039715,000163: 21,2325           74741                           MP       BIT4                                  
039716,000164: 21,2326           30001                           CA       L                                     #  FETCH DT FROM L IN UNITS OF 2(11) CS
039717,000165: 21,2327           00006                           EXTEND                                         
039718,000166: 21,2330           70063                           MP       ALTRTEMP                              
039719,000167: 21,2331           53731                           DXCH     ALTITUDE                              
039720,000168: 21,2332           00006                           EXTEND                                         
039721,000169: 21,2333           31710                           DCA      HCALCLAD                              
039722,000170: 21,2334           21731                           DAS      ALTITUDE                              #  ALTITUDE IN UNITS OF 2(15) METERS
039723,000171: 
039724,000172:                                                                                                  #  ************************************************************************
039725,000173:                                                                                                  #  SEND OUT ALTITUDE-RATE IF POSSIBLE
039726,000174:                                                                                                  #  ************************************************************************
039727,000175: 

Page 898

039729,000177: 21,2335           40075                           CS       FLAGWRD1                              #  IS INITIALIZATION IN ORDER?
039730,000178: 21,2336           74727                           MASK     DIDFLBIT                              
039731,000179: 21,2337           10000                           CCS      A                                     
039732,000180: 21,2340           12626                           TCF      DISPINIT                              #  YES:  THEN GO DO IT
039733,000181: 
039734,000182: 21,2341           34743                           CAF      BIT2                                  #  NO:   ARE RR ERROR COUNTERS ENABLED?
039735,000183: 21,2342           00006                           EXTEND                                         
039736,000184: 21,2343           02012                           RAND     CHAN12                                
039737,000185: 21,2344           00006                           EXTEND                                         
039738,000186: 21,2345           12653                           BZF      DISPRSET                              #  NO:   REINITIALIZE DISPLAYS
039739,000187: 21,2346           00006        ALTRROUT           EXTEND                                         #  YES:  SIGNIFY ALTITUDE-RATE (BIT2 IN A)
039740,000188: 21,2347           05014                           WOR      CHAN14                                
039741,000189: 
039742,000190: 21,2350           00006                           EXTEND                                         
039743,000191: 21,2351           31727                           DCA      ALTRATE                               
039744,000192: 21,2352           20001                           DDOUBL                                         #  RESCALE ALTRATE TO UNITS OF 2(2) M/CS
039745,000193: 21,2353           20001                           DDOUBL                                         
039746,000194: 21,2354           20001                           DDOUBL                                         
039747,000195: 21,2355           00006                           EXTEND                                         
039748,000196: 21,2356           72004                           MP       ALTRCONV                              #  RESCALE TO UNITS OF .5 F/S/BIT
039749,000197: 
039750,000198: 21,2357           56001                           XCH      L                                     #  ROUND TO NEAREST .5 F/S
039751,000199: 21,2360           60000                           DOUBLE                                         
039752,000200: 21,2361           54002                           TS       Q                                     
039753,000201: 21,2362           34746                           CAF      ZERO                                  
039754,000202: 21,2363           26001                           ADS      L                                     
039755,000203: 
039756,000204: 21,2364           64726                           AD       NEGMAX                                
039757,000205: 21,2365           54001                           TS       L                                     
039758,000206: 21,2366           12371                           TCF      +3                                    
039759,000207: 21,2367           60001                           AD       L                                     
039760,000208: 21,2370           40000                           COM                                            
039761,000209: 21,2371           56060                 +3        XCH      ALTM                                  
039762,000210: 
039763,000211: 21,2372           34742                           CAF      BIT3                                  
039764,000212: 21,2373           00006                           EXTEND                                         
039765,000213: 21,2374           05014                           WOR      CHAN14                                
039766,000214: 
039767,000215: 21,2375           35745                           CA       TWELVE                                #  DELAY 120 MS FOR DATA OUTPUT
039768,000216:                                                                                                  #  NOTE - THIS DELAY MUST BE GREATER THAN
039769,000217:                                                                                                  #  100 MS FOR COMPATIBILITY WITH THE LMS
039770,000218: 21,2376           05226                           TC       VARDELAY                              
039771,000219: 
039772,000220: 21,2377           44743        ALTROUT            CS       BIT2                                  #  SIGNIFY ALTITUDE
039773,000221: 21,2400           00006                           EXTEND                                         
039774,000222: 21,2401           03014                           WAND     CHAN14                                
039775,000223: 
039776,000224: 21,2402           31731                           CA       ALTITUDE   +1                         
039777,000225: 21,2403           00006                           EXTEND                                         
039778,000226: 21,2404           72005                           MP       ALTCONV                               
039779,000227: 

Page 899

039781,000229: 21,2405           54001                           TS       L                                     
039782,000230: 21,2406           34746                           CAF      ZERO                                  
039783,000231: 21,2407           52064                           DXCH     ALTTEMP                               
039784,000232: 21,2410           31730                           CA       ALTITUDE                              
039785,000233: 21,2411           00006                           EXTEND                                         
039786,000234: 21,2412           72005                           MP       ALTCONV                               
039787,000235: 21,2413           20064                           DAS      ALTTEMP                               #  ALTITUDE IN UNITS OF 9.380 FEET/BIT
039788,000236: 
039789,000237: 21,2414           52064                           DXCH     ALTTEMP                               
039790,000238: 21,2415           20001                           DDOUBL                                         
039791,000239: 21,2416           20001                           DDOUBL                                         #  RESCALE TO UNITS OF 2.345 FEET/BIT
039792,000240: 21,2417           54000                           OVSK                                           
039793,000241: 21,2420           12424                           TCF      +4                                    #  NO OVERFLOW:  -38420 < ALTITUDE < +38420
039794,000242: 
039795,000243: 21,2421           74724                           MASK     POSMAX                                #  RESET OVERFLOW
039796,000244: 21,2422           64726                           AD       BIT15                                 
039797,000245: 21,2423           12430                           TCF      +5                                    
039798,000246: 
039799,000247: 21,2424           10000                 +4        CCS      A                                     #  APPLY LOWER LIMIT OF POSITIVE ZERO
039800,000248: 21,2425           64744                           AD       ONE                                   
039801,000249: 21,2426           12430                           TCF      +2                                    
039802,000250: 21,2427           34746                           CAF      ZERO                                  
039803,000251: 
039804,000252: 21,2430           56060                 +5        XCH      ALTM                                  
039805,000253: 21,2431           34742                           CAF      BIT3                                  
039806,000254: 21,2432           00006                           EXTEND                                         
039807,000255: 21,2433           05014                           WOR      CHAN14                                
039808,000256: 
039809,000257:                                                                                                  #  ************************************************************************
039810,000258:                                                                                                  #  SEND OUT FORWARD AND LATERAL VELOCITIES
039811,000259:                                                                                                  #  ************************************************************************
039812,000260: 
039813,000261: 21,2434           02513                           TC       CROSCOMP                              #  FIRST CALL SUBROUTINE TO COMPUTE THEM
039814,000262: 
039815,000263: 21,2435           34733                           CAF      BIT10                                 #  1/32 TO ITEMP2 FOR USE AS DIVISOR BELOW
039816,000264: 21,2436           54062                           TS       ITEMP2                                
039817,000265: 
039818,000266: 21,2437           32001                           CAF      MAXVEL                                #  LIMIT COMMAND TO 198.645 F/S
039819,000267: 21,2440           22070                           LXCH     FORVTEMP                              
039820,000268: 21,2441           02673                           TC       LADLIMIT                              
039821,000269: 21,2442           22071                           LXCH     FORVTEMP   +1                         
039822,000270: 21,2443           00006                           EXTEND                                         #  RESCALE TO UNITS OF ONE M/CS
039823,000271: 21,2444           10062                           DV       ITEMP2                                
039824,000272: 21,2445           00006                           EXTEND                                         #  RESCALE TO UNITS OF .5571 F/S/BIT
039825,000273: 21,2446           72003                           MP       VELCONV                               
039826,000274: 21,2447           56001                           XCH      L                                     #  ROUND TO NEAREST .5571 F/S
039827,000275: 21,2450           60000                           DOUBLE                                         
039828,000276: 21,2451           54002                           TS       Q                                     
039829,000277: 21,2452           12454                           TCF      FORVOUT                               
039830,000278: 21,2453           26001                           ADS      L                                     
039831,000279: 

Page 900

039833,000281: 21,2454           41733        FORVOUT            CS       FORVMETR                              #  SUBTRACT METER INDICATOR TO GET CHANGE
039834,000282: 21,2455           26001                           ADS      L                                     
039835,000283: 21,2456           32002                           CA       MAXDBITS                              
039836,000284: 21,2457           02673                           TC       LADLIMIT                              #  LIMIT CHANGE TO ABOUT 300 F/S
039837,000285: 21,2460           64745                           AD       NEG0                                  
039838,000286: 21,2461           54054                           TS       CDUSCMD                               
039839,000287: 21,2462           27733                           ADS      FORVMETR                              #  UPDATE METER INDICATOR
039840,000288: 
039841,000289: 21,2463           32001                           CAF      MAXVEL                                #  LIMIT COMMAND TO 198.645 F/S
039842,000290: 21,2464           22072                           LXCH     LATVEL                                
039843,000291: 21,2465           02673                           TC       LADLIMIT                              
039844,000292: 21,2466           22073                           LXCH     LATVEL     +1                         
039845,000293: 21,2467           00006                           EXTEND                                         #  RESCALE TO UNITS OF ONE M/CS
039846,000294: 21,2470           10062                           DV       ITEMP2                                
039847,000295: 21,2471           00006                           EXTEND                                         #  RESCALE TO UNITS OF .5571 F/S/BIT
039848,000296: 21,2472           72003                           MP       VELCONV                               
039849,000297: 21,2473           56001                           XCH      L                                     #  ROUND TO NEAREST .5571 F/S
039850,000298: 21,2474           60000                           DOUBLE                                         
039851,000299: 21,2475           54002                           TS       Q                                     
039852,000300: 21,2476           12500                           TCF      LATVOUT                               
039853,000301: 21,2477           26001                           ADS      L                                     
039854,000302: 21,2500           41732        LATVOUT            CS       LATVMETR                              #  SUBTRACT METER INDICATOR TO GET CHANGE
039855,000303: 21,2501           26001                           ADS      L                                     
039856,000304: 21,2502           32002                           CAF      MAXDBITS                              
039857,000305: 21,2503           02673                           TC       LADLIMIT                              #  LIMIT CHANGE TO ABOUT 300 F/S
039858,000306: 21,2504           64745                           AD       NEG0                                  
039859,000307: 21,2505           54053                           TS       CDUTCMD                               
039860,000308: 21,2506           27732                           ADS      LATVMETR                              #  UPDATE METER INDICATOR
039861,000309: 
039862,000310: 21,2507           35011                           CAF      BITSET                                #  SET DRIVE BITS
039863,000311: 21,2510           00006                           EXTEND                                         
039864,000312: 21,2511           05014                           WOR      CHAN14                                
039865,000313: 
039866,000314: 21,2512           05263        LANADEND           TC       TASKOVER                              
039867,000315: 
039868,000316:                                                                                                  #  ************************************************************************
039869,000317:                                                                                                  #  SUBROUTINE TO COMPUTE FORWARD AND LATERAL VELOCITIES
039870,000318:                                                                                                  #  ************************************************************************
039871,000319: 
039872,000320:                                                                                                  #      THE SCALARS VHY AND VHZ, COMPUTED NEXT, ARE THE VELOCITIES ALONG UNIT VECTORS UHYP AND UHZP. UHYP NORMAL
039873,000321:                                                                                                  #  TO THE PRE-PDI ORBITAL PLANE, UHZP IN TURN NORMAL TO UHYP AND THE POSITION VECTOR.  NOW SINCE FOR THE "LANDING
039874,000322:                                                                                                  #  ALIGNMENT" OF THE IMU THE STABLE-MEMBER Y-AXIS IS DEFINED THE SAME WAY AS UHYP, VVECTY IS PRECISELY VHY.
039875,000323:                                                                                                  #  FURTHERMORE, THE Y-TERM OF THE VHZ COMPUTATION DROPS OUT, AND THE FOLLOWING USEFUL EQUALITIES BECOME TRUE:
039876,000324:                                                                                                  #  UHZPX = - RUNITZ AND UHZPZ = RUNITX.  DRAW A PICTURE TO BE CONVINCED.
039877,000325: 
039878,000326:                                                                                                  #      NOTE THAT IN THIS VERSION CROSS-POINTER DISPLAYS ARE OUTPUT DURING ASCENT AND ABORTS AS WELL AS DESCENT.
039879,000327: 
039880,000328: 21,2513           40074        CROSCOMP           CS       FLAGWRD0                              #  IS R10FLAG SET TO INDICATE ASCENT?
039881,000329: 21,2514           74743                           MASK     R10FLBIT                              
039882,000330: 21,2515           00006                           EXTEND                                         
039883,000331: 

Page 901

039885,000333: 21,2516           12615                           BZF      APSLAD                                #  YES:  DISPLAY LATVEL IN INERTIAL AXES
039886,000334: 
039887,000335: 21,2517           41716                           CS       RUNITZ                                #  NO:   COMPUTE DOWNRANGE VELOCITY
039888,000336: 21,2520           00006                           EXTEND                                         
039889,000337: 21,2521           71720                           MP       VVECTX                                
039890,000338: 21,2522           52066                           DXCH     VHZ                                   
039891,000339: 21,2523           31714                           CA       RUNITX                                
039892,000340: 21,2524           00006                           EXTEND                                         
039893,000341: 21,2525           71724                           MP       VVECTZ                                
039894,000342: 21,2526           20066                           DAS      VHZ                                   
039895,000343: 21,2527           31714                           CA       RUNITX                                #  COMPUTE THE MORE SENSITIVE TERM IN DP
039896,000344: 21,2530           00006                           EXTEND                                         
039897,000345: 21,2531           71725                           MP       VVECTZ     +1                         
039898,000346: 21,2532           54001                           TS       L                                     
039899,000347: 21,2533           34746                           CAF      ZERO                                  
039900,000348: 21,2534           20066                           DAS      VHZ                                   #  VHZ IN UNITS OF 2(5) M/CS
039901,000349: 
039902,000350: 21,2535           00006                           EXTEND                                         
039903,000351: 21,2536           31723                           DCA      VVECTY                                
039904,000352: 21,2537           52064                           DXCH     VHY                                   #  VHY IN UNITS OF 2(5) M/CS
039905,000353: 
039906,000354: 21,2540           35006                           CAF      EBANK6                                #  SWITCH TO DAP EBANK
039907,000355: 21,2541           54003                           TS       EBANK                                 
039908,000356: 21,2542  E6,1417                                  EBANK=   M22                                   
039909,000357: 
039910,000358: 21,2542           31420                           CA       M32                                   #  COS(AOG)
039911,000359: 21,2543           00006                           EXTEND                                         
039912,000360: 21,2544           70065                           MP       VHZ                                   
039913,000361: 21,2545           52071                           DXCH     FORVTEMP                              
039914,000362: 21,2546           41417                           CS       M22                                   #  SIN(AOG)
039915,000363: 21,2547           00006                           EXTEND                                         
039916,000364: 21,2550           70063                           MP       VHY                                   
039917,000365: 21,2551           20071                           DAS      FORVTEMP                              
039918,000366: 
039919,000367: 21,2552           31420                           CA       M32                                   #  COS(AOG)
039920,000368: 21,2553           00006                           EXTEND                                         
039921,000369: 21,2554           70066                           MP       VHZ        +1                         
039922,000370: 21,2555           54062                           TS       ITEMP2                                
039923,000371: 21,2556           41417                           CS       M22                                   #  SIN(AOG)
039924,000372: 21,2557           00006                           EXTEND                                         
039925,000373: 21,2560           70064                           MP       VHY        +1                         
039926,000374: 21,2561           60062                           AD       ITEMP2                                
039927,000375: 21,2562           54001                           TS       L                                     
039928,000376: 21,2563           34746                           CAF      ZERO                                  
039929,000377: 21,2564           20071                           DAS      FORVTEMP                              #  FORWARD VELOCITY IN UNITS OF 2(5) M/CS
039930,000378: 
039931,000379: 21,2565           31417                           CA       M22                                   #  SIN(AOG)
039932,000380: 21,2566           00006                           EXTEND                                         
039933,000381: 21,2567           70065                           MP       VHZ                                   
039934,000382: 21,2570           52073                           DXCH     LATVEL                                
039935,000383: 

Page 902

039937,000385: 21,2571           31420                           CA       M32                                   #  COS(AOG)
039938,000386: 21,2572           00006                           EXTEND                                         
039939,000387: 21,2573           70063                           MP       VHY                                   
039940,000388: 21,2574           20073                           DAS      LATVEL                                
039941,000389: 
039942,000390: 21,2575           31417                           CA       M22                                   #  SIN(AOG)
039943,000391: 21,2576           00006                           EXTEND                                         
039944,000392: 21,2577           70066                           MP       VHZ        +1                         
039945,000393: 21,2600           54062                           TS       ITEMP2                                
039946,000394: 21,2601           31420                           CA       M32                                   #  COS(AOG)
039947,000395: 21,2602           00006                           EXTEND                                         
039948,000396: 21,2603           70064                           MP       VHY        +1                         
039949,000397: 21,2604           60062                           AD       ITEMP2                                
039950,000398: 21,2605           54001                           TS       L                                     
039951,000399: 21,2606           34746                           CAF      ZERO                                  
039952,000400: 21,2607           20073                           DAS      LATVEL                                #  LATERAL VELOCITY IN UNITS OF 2(5) M/CS
039953,000401: 
039954,000402: 21,2610           24006                           INCR     BBANK                                 #  RETURN TO SERVICER EBANK
039955,000403: 21,2611  E7,1711                                  EBANK=   HDOTLAD                               
039956,000404: 
039957,000405: 21,2611           00006        CROSSOUT           EXTEND                                         #  MOVE FORVTEMP TO FORVEL FOR DSKY DISPLAY
039958,000406: 21,2612           30071                           DCA      FORVTEMP                              
039959,000407: 21,2613           53735                           DXCH     FORVEL                                
039960,000408: 
039961,000409: 21,2614           00002                           TC       Q                                     
039962,000410: 
039963,000411: 21,2615           54070        APSLAD             TS       FORVTEMP                              #  DURING ASCENT AND ABORTS COME HERE TO
039964,000412: 21,2616           54071                           TS       FORVTEMP   +1                         #    DISPLAY LATVEL = SM Y-AXIS VELOCITY
039965,000413: 
039966,000414: 21,2617           00006                           EXTEND                                         
039967,000415: 21,2620           31723                           DCA      VVECTY                                
039968,000416: 21,2621           52073                           DXCH     LATVEL                                
039969,000417: 21,2622           00006                           EXTEND                                         #  ADD SURFACE VELOCITY BACK IN SO APS
039970,000418: 21,2623           31704                           DCA      VSURFACE   +2                         #    LATVEL DISPLAY WILL BE IN TRUE
039971,000419: 21,2624           20073                           DAS      LATVEL                                #    STABLE-MEMBER COORDINATES
039972,000420: 
039973,000421: 21,2625           12611                           TCF      CROSSOUT                              #  REJOIN THE MAINSTREAM
039974,000422: 
039975,000423:                                                                                                  #  ************************************************************************
039976,000424:                                                                                                  #  LANDING ANALOG DISPLAYS INITIALIZATION
039977,000425:                                                                                                  #  ************************************************************************
039978,000426: 
039979,000427: 21,2626           02513        DISPINIT           TC       CROSCOMP                              #  FIRST COMPUTE BUT NOT OUTPUT VELOCITIES
039980,000428: 
039981,000429: 21,2627           40075                           CS       FLAGWRD1                              #  SET DIDFLAG
039982,000430: 21,2630           74727                           MASK     DIDFLBIT                              
039983,000431: 21,2631           26075                           ADS      FLAGWRD1                              
039984,000432: 
039985,000433: 21,2632           34735                           CAF      BIT8                                  #  SET DISPLAY INERTIAL DATA OUTBIT
039986,000434: 21,2633           00006                           EXTEND                                         
039987,000435: 

Page 903

039989,000437: 21,2634           05012                           WOR      CHAN12                                
039990,000438: 
039991,000439: 21,2635           44746                           CS       ZERO                                  #  ZERO METER INDICATORS
039992,000440: 21,2636           55732                           TS       LATVMETR                              
039993,000441: 21,2637           55733                           TS       FORVMETR                              
039994,000442: 
039995,000443: 21,2640           34741                           CAF      BIT4                                  #  SET UP TASK TO FINISH INITIALIZATION
039996,000444: 21,2641           05175                           TC       TWIDDLE                               
039997,000445: 21,2642           02644                           ADRES    INTLZE                                
039998,000446: 21,2643           12512                           TCF      LANADEND                              
039999,000447: 
040000,000448: 21,2644           34743        INTLZE             CAF      BIT2                                  #  ENABLE RR ERROR COUNTER
040001,000449: 21,2645           00006                           EXTEND                                         
040002,000450: 21,2646           05012                           WOR      CHAN12                                
040003,000451: 
040004,000452: 21,2647           41300                           CS       IMODES33                              #  SET INERTIAL DATA FLAG
040005,000453: 21,2650           74735                           MASK     BIT8                                  
040006,000454: 21,2651           27300                           ADS      IMODES33                              
040007,000455: 21,2652           05263                           TC       TASKOVER                              
040008,000456: 
040009,000457:                                                                                                  #  ************************************************************************
040010,000458:                                                                                                  #  LANDING ANALOG DISPLAYS RESET ROUTINE
040011,000459:                                                                                                  #  ************************************************************************
040012,000460: 
040013,000461: 21,2653           02513        DISPRSET           TC       CROSCOMP                              #  FIRST COMPUTE BUT NOT OUTPUT VELOCITIES
040014,000462: 
040015,000463: 21,2654           44727                 +1        CS       DIDFLBIT                              #  RESET DIDFLAG
040016,000464: 21,2655           70075                           MASK     FLAGWRD1                              
040017,000465: 21,2656           54075                           TS       FLAGWRD1                              
040018,000466: 
040019,000467: 21,2657           34735                           CAF      BIT8                                  #  WAS INERTIAL DATA JUST DISPLAYED?
040020,000468: 21,2660           71300                           MASK     IMODES33                              
040021,000469: 21,2661           10000                           CCS      A                                     
040022,000470: 21,2662           34743                           CAF      BIT2                                  #  YES:  DISABLE RR ERROR COUNTER AND
040023,000471: 21,2663           64735                           AD       BIT8                                  #  NO:   RESET DISPLAY INERTIAL DATA OUTBIT
040024,000472: 21,2664           40000                           COM                                            
040025,000473: 21,2665           00006                           EXTEND                                         
040026,000474: 21,2666           03012                           WAND     CHAN12                                
040027,000475: 
040028,000476: 21,2667           44735                           CS       BIT8                                  
040029,000477: 21,2670           71300                           MASK     IMODES33                              
040030,000478: 21,2671           55300                           TS       IMODES33                              
040031,000479: 21,2672           12512                           TCF      LANADEND                              
040032,000480: 
040033,000481:                                                                                                  #  ************************************************************************
040034,000482:                                                                                                  #  CONSTANTS FOR LANDING ANALOG DISPLAYS
040035,000483:                                                                                                  #  ************************************************************************
040036,000484: 
040037,000485:                                                                                                  #  CONSTANTS ON A-CARDS ARE FOUND IN THE CONTROLLED CONSTANTS SECTION
040038,000486: 

Page 904

040040,000488:                                                                                                  #  LANAKPIP        DEC             .0512                 SCALES PIPAS TO UNITS OF 2(5) M/CS
040041,000489: 
040042,000490:                                                                                                  #  MAXVEL          OCT             00466                 198.645 F/S IN UNITS OF 2(5) M/CS
040043,000491: 
040044,000492:                                                                                                  #  MAXDBITS        OCT             01034                 ABOUT 300 F/S
040045,000493: 
040046,000494:                                                                                                  #  VELCONV         DEC             .03594                SCALES VEL AT ONE M/CS TO .5571 F/S/BIT
040047,000495: 
040048,000496:                                                                                                  #  ALTRCONV        DEC             .16020                SCALES ALTR AT 2(2) M/CS TO .5 F/S/BIT
040049,000497: 
040050,000498:                                                                                                  #  ALTCONV         DEC             .69954                SCALES ALTITUDE AT 2(15) M TO 9.38 F/BIT
040051,000499: 
040052,000500: 21,2673     5011               BITSET             =        PRIO6                                 #  CROSS-POINTER DRIVE BITS
040053,000501: 
040054,000502:                                                                                                  #  ************************************************************************
040055,000503:                                                                                                  #  SUBROUTINES
040056,000504:                                                                                                  #  ************************************************************************
040057,000505: 21,2673           54061        LADLIMIT           TS       ITEMP1                                
040058,000506: 21,2674           34746                           CAF      ZERO                                  
040059,000507: 21,2675           00006                           EXTEND                                         
040060,000508: 21,2676           10061                           DV       ITEMP1                                
040061,000509: 21,2677           10000                           CCS      A                                     
040062,000510: 21,2700           22061                           LXCH     ITEMP1                                
040063,000511: 21,2701           12703                           TCF      +2                                    
040064,000512: 21,2702           12705                           TCF      +3                                    
040065,000513: 21,2703           30001                           CA       L                                     
040066,000514: 21,2704           00002                           TC       Q                                     
040067,000515: 21,2705           40061                           CS       ITEMP1                                
040068,000516: 21,2706           00002                           TC       Q                                     
040069,000517: 
040070,000518:                                                                                                  #  ************************************************************************
040071,000519:                                                                                                  #  THE END OF THE LANDING ANALOG DISPLAYS
040072,000520:                                                                                                  #  ************************************************************************

End of include-file LANDING_ANALOG_DISPLAYS.agc.  Parent file is MAIN.agc