### FILE="Main.annotation"
## Copyright:   Public domain.
## Filename:    T6-RUPT_PROGRAMS.agc
## Purpose:     A section of a reconstructed, mixed version of Sundance
##              It is part of the reconstructed source code for the Lunar
##              Module's (LM) Apollo Guidance Computer (AGC) for Apollo 9.
##              No original listings of this program are available;
##              instead, this file was created via disassembly of dumps
##              of various revisions of Sundance core rope modules.
## Assembler:   yaYUL
## Contact:     Ron Burkey <info@sandroid.org>.
## Website:     www.ibiblio.org/apollo/index.html
## Mod history: 2020-06-17 MAS  Created from Luminary 69.

## Sundance 302

# PROGRAM NAMES:        (1) T6JOBCHK    MOD. NO. 5      OCTOBER 2, 1967
#                       (2) DOT6RUPT
# MODIFICATION BY:      LOWELL G HULL (A.C.ELECTRONICS)
#
# THESE PROGRAMS ENABLE THE LM DAP TO CONTROL THE THRUST TIMES OF THE REACTION CONTROL SYSTEM JETS BY USING TIME6.
# SINCE THE LM DAP MAINTAINS EXCLUSIVE CONTROL OVER TIME6 AND ITS INTERRUPTS, THE FOLLOWING CONVENTIONS HAVE BEEN
# ESTABLISHED AND MUST NOT BE TAMPERED WITH:
#       1.      NO NUMBER IS EVER PLACED INTO TIME6 EXCEPT BY LM DAP.
#       2.      NO PROGRAM OTHER THAN LM DAP ENABLES THE TIME6 COUNTER.
#       3.      TO USE TIME6, THE FOLLOWING SEQUENCE IS ALWAYS EMPLOYED:
#               A.      A POSITIVE (NON-ZERO) NUMBER IS STORED IN TIME6.
#               B.      THE TIME6 CLOCK IS ENABLED.
#               C.      TIME6 IS INTERROGATED AND IS:
#                       I.      NEVER FOUND NEGATIVE (NON-ZERO) OR +0.
#                       II.     SOMETIMES FOUND POSITIVE (BETWEEN 1 AND 240D) INDICATING THAT IT IS ACTIVE.
#                       III.    SOMETIMES FOUND POSMAX INDICATING THAT IT IS INACTIVE AND NOT ENABLED.
#                       IV.     SOMETIMES FOUND NEGATIVE ZERO INDICATING THAT:
#                               A.      A T6RUPT IS ABOUT TO OCCUR AT THE NEXT DINC, OR
#                               B.      A T6RUPT IS WAITING IN THE PRIORITY CHAIN, OR
#                               C.      A T6RUPT IS IN PROCESS NOW.
#       4)      ALL PROGRAMS WHICH OPERATE IN EITHER INTERRUPT MODE OR WITH INTERRUPT INHIBITED MUST CALL T6JOBCHK
#               EVERY 5 MILLISECONDS TO PROCESS A POSSIBLE WAITING T6RUPT BEFORE IT CAN BE HONORED BY THE HARDWARE.
#      (5.      PROGRAM JTLST, IN Q,R-AXES, HANDLES THE INPUT LIST.)
#
# T6JOBCHK CALLING SEQUENCE:
#               L       TC      T6JOBCHK
#               L+1     (RETURN)
#
# DOT6RUPT CALLING SEQUENCE:
#                       DXCH    ARUPT           T6RUPT LEAD IN AT LOCATION 4004.
#                       EXTEND
#                       DCA     T6ADR
#                       DTCB
#
# SUBROUTINES CALLED:   DOT6RUPT CALLS T6JOBCHK.
#
# NORMAL EXIT MODES:    T6JOBCHK RETURNS TO L +1.
#                       DOT6RUPT TRANSFERS CONTROL TO RESUME.
#
# ALARM/ABORT MODES:    NONE.
#
# INPUT:        TIME6           NXT6ADR         OUTPUT:         TIME6           NXT6ADR         CHANNEL 5
#               T6NEXT          T6NEXT +1                       T6NEXT          T6NEXT +1       CHANNEL 6
#               T6FURTHA        T6FURTHA +1                     T6FURTHA        T6FURTHA +1     BIT15/CH13
#
# DEBRIS:       T6JOBCHK CLOBBERS A.  DOT6RUPT CLOBBERS NOTHING.

                BLOCK   02
                BANK    16
                SETLOC  DAPS1
                BANK
                EBANK=  T6NEXT
                COUNT*  $$/DAPT6

T6JOBCHK        CCS     TIME6           # CHECK TIME6 FOR WAITING T6RUPT:
                TC      Q               # NONE: CLOCK COUTING DOWN.
                TC      CCSHOLE
                TC      T6JOBCHK +3

# CONTROL PASSES TO T6JOB ONLY WHEN C(TIME6) = -0 (I.E. WHEN A T6RUPT MUST BE PROCESSED).

T6JOB           CAF     POSMAX          # DISABLE CLOCK: NEEDED SINCE RUPT OCCURS
                EXTEND                  # 1 DINC AFTER T6 = 77777. FOR 625 MUSECS
                WAND    CHAN13          # MUST NOT HAVE T6 = +0 WITH ENABLE SET

                CA      POSMAX
                ZL
                DXCH    T6FURTHA
                DXCH    T6NEXT
                LXCH    NXT6ADR
                TS      TIME6

                AD      PRIO37
                TS      A
                TCF     ENABLET6
                CA      POSMAX
                TS      TIME6
                TCF     GOCH56
ENABLET6        CA      BIT15
                EXTEND
                WOR     CHAN13
                CA      T6NEXT
                AD      PRIO37
                TS      A
                TCF     GOCH56
                CA      POSMAX
                TS      T6NEXT
GOCH56          INDEX   L
                TCF     WRITEP -1

## Sundance 292

                BLOCK   02
                SETLOC  FFTAG9
                BANK
                EBANK=  CDUXD
                COUNT*  $$/DAPT6

NARROWDB        OCTAL   00155           # 0.3 DEGREE SCALED AT 45.
WIDEDB          OCTAL   03434           # 5.0 DEGREES SCALED AT 45.

                EBANK=  T6NEXT
T6ADR           2CADR   DOT6RUPT        # 2CADR OF INTERRUPT PROCESSOR.

                CA      NEXTP
WRITEP          EXTEND
                WRITE   CHAN6
                TC      Q

                CA      NEXTU
WRITEU          TS      L
                CS      00314OCT
                EXTEND
                RAND    CHAN5
                AD      L
                EXTEND
                WRITE   CHAN5
                TC      Q

                CA      NEXTV
WRITEV          TS      L
                CA      00314OCT
                TCF     -9D
00314OCT        OCT     00314

## Sundance 302

                BANK    16
                SETLOC  DAPS1
                BANK

                EBANK=  T6NEXT
                COUNT*  $$/DAPT6

DOT6RUPT        LXCH    BANKRUPT        # (INTERRUPT LEAD INS CONTINUED)
                EXTEND
                QXCH    QRUPT

                TC      T6JOBCHK        # CALL T6JOBCHK.

                TCF     RESUME          # END TIME6 INTERRUPT PROCESSOR.