MYSUBS

Scanned pages: 999-1001
# Copyright:  Public domain.
# Filename:  MYSUBS.agc
# Purpose:  Part of the source code for Colossus 2A, AKA Comanche 055.
#    It is part of the source code for the Command Module's (CM)
#    Apollo Guidance Computer (AGC), for Apollo 11.
# Assembler:  yaYUL
# Contact:  Ron Burkey <info@sandroid.org>.
# Website:  www.ibiblio.org/apollo.
# Pages:  999-1001
# Mod history:  2009-05-13 RSB  Adapted from the Colossus249/ file of the
#        same name, using Comanche055 page images.
#    2009-05-20 RSB  Corrections: EBANK= changed from MPAC to KMPAC.
#
# 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

# Page 999
    BANK  20
    SETLOC  MYSUBS
    BANK

    EBANK=  KMPAC
SPCOS1    EQUALS  SPCOS
SPSIN1    EQUALS  SPSIN
SPCOS2    EQUALS  SPCOS
SPSIN2    EQUALS  SPSIN


    COUNT  21/DAPMS

# ONE AND ONE HALF PRECISION MULTIPLICATION ROUTINE

SMALLMP    TS  KMPTEMP    # A(X+Y)
    EXTEND
    MP  KMPAC   +1
    TS  KMPAC   +1  # AY
    CAF  ZERO
    XCH  KMPAC
    EXTEND
    MP  KMPTEMP    # AX
    DAS  KMPAC    # AX+AY
    TC  Q


# SUBROUTINE FOR DOUBLE PRECISION ADDITIONS OF ANGLES
# A AND L CONTAIN A DP(1S) ANGLE SCALED BY 180 DEGS TO BE ADDED TO KMPAC.
# RESULT IS PLACED IN KMPAC.  TIMING = 6 MCT (22 MCT ON OVERFLOW)

DPADD    DAS  KMPAC
    EXTEND
    BZF  TSK   +1  # NO OVERFLOW
    CCS  KMPAC
    TCF  DPADD+    # + OVERFLOW
    TCF  +2
    TCF  DPADD-    # - OVERFLOW
    CCS  KMPAC   +1
    TCF  DPADD2+    # UPPER = 0, LOWER +
    TCF  +2
    COM      # UPPER = 0, LOWER -
    AD  POSMAX    # LOWER = 0, A=0
    TS  KMPAC   +1  # CAN NOT OVERFLOW
    CA  POSMAX    # UPPER WAS = 0
TSK    TS  KMPAC
    TC  Q

DPADD+    AD  NEGMAX    # KMPAC GREATER THAN 0
    TCF  TSK

# Page 1000
DPADD-    COM
    AD  POSMAX    # KMPAC LESS THAN 0
    TCF  TSK

DPADD2+    AD  NEGMAX    # CAN NOT OVERFLOW
    TS  KMPAC   +1
    CA  NEGMAX    # UPPER WAS = 0
    TCF  TSK

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