INTER-BANK_COMMUNICATION.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: INTER-BANK_COMMUNICATION.agc
## Purpose: Part of the source code for Colossus, build 249.
## It is part of the source code for the Command Module's (CM)
## Apollo Guidance Computer (AGC), for Apollo 9.
## Assembler: yaYUL
## Reference: Starts on p. 1073
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo.
## Mod history: 08/28/04 RSB Adapted from corresponding Luminary 131 file.
## 2011-05-07 JL Removed workaround.
## 2017-01-06 RSB Page numbers now agree with those on the
## original harcopy, as opposed to the PDF page
## numbers in 1701.pdf.
## 2017-01-14 RSB Cross-diff'd comment text (not whitespace)
## vs the already-proofed corresponding Colossus
## 237 and Comanche 55 source-code files
## and corrected errors found. After this process,
## there was no difference between the 3 versions,
## in terms of comment text.
##
## The contents of the "Colossus249" files, in general, are transcribed
## from a scanned copy of the program listing. Notations on this
## document read, in part:
##
## Assemble revision 249 of AGC program Colossus by NASA
## 2021111-041. October 28, 1968.
##
## This AGC program shall also be referred to as
## Colossus 1A
##
## Prepared by
## Massachusetts Institute of Technology
## 75 Cambridge Parkway
## Cambridge, Massachusetts
## under NASA contract NAS 9-4065.
##
## Refer directly to the online document mentioned above for further information.
## Please report any errors (relative to the scanned pages) to info@sandroid.org.
##
## In some cases, where the source code for Luminary 131 overlaps that of
## Colossus 249, this code is instead copied from the corresponding Luminary 131
## source file, and then is proofed to incorporate any changes.
## Page 1073
# THE FOLLOWING ROUTINE CAN BE USED TO CALL A SUBROUTINE IN ANOTHER BANK. IN THE BANKCALL VERSION, THE
# CADR OF THE SUBROUTINE IMMEDIATELY FOLLOWS THE TC BANKCALL INSTRUCTION, WITH C(A) AND C(L) PRESERVED.
BLOCK 02
COUNT 02/BANK
BANKCALL DXCH BUF2 # SAVE INCOMING A,L.
INDEX Q # PICK UP CADR.
CA 0
INCR Q # SO WE RETURN TO THE LOC. AFTER THE CADR.
# SWCALL IS IDENTICAL TO BANKCALL, EXCEPT THAT THE CADR ARRIVES IN A.
SWCALL TS L
LXCH FBANK # SWITCH BANKS, SAVING RETURN.
MASK LOW10 # GET SUB-ADDRESS OF CADR.
XCH Q # A,L NOW CONTAINS DP RETURN.
DXCH BUF2 # RESTORING INPUTS IF THIS IS A BANKCALL.
INDEX Q
TC 10000 # SETTING Q TO SWRETURN.
SWRETURN XCH BUF2 +1 # COMES HERE TO RETURN TO CALLER. C(A,L)
XCH FBANK # ARE PRESERVED FOR RETURN.
XCH BUF2 +1
TC BUF2
# THE FOLLOWING ROUTINE CAN BE USED AS A UNILATERAL JUMP WITH C(A,L) PRESERVED AND THE CADR IMMEDIATELY
# FOLLOWING THE TC POSTJUMP INSTRUCTION.
POSTJUMP XCH Q # SAVE INCOMING C(A).
INDEX A # GET CADR.
CA 0
# BANKJUMP IS THE SAME AS POSTJUMP, EXCEPT THAT THE CADR ARRIVES IN A.
BANKJUMP TS FBANK
MASK LOW10
XCH Q # RESTORING INPUT C(A) IF THIS WAS A
Q+10000 INDEX Q # POSTJUMP.
PRIO12 TCF 10000 # PRIO12 = TCF 10000 = 12000
## Page 1074
# THE FOLLOWING ROUTINE GETS THE RETURN CADR SAVED BY SWCALL OR BANKCALL AND LEAVES IT IN A.
MAKECADR CAF LOW10
MASK BUF2
AD BUF2 +1
TC Q
SUPDACAL TS MPTEMP
XCH FBANK # SET FBANK FOR DATA.
EXTEND
ROR SUPERBNK # SAVE FBANK IN BITS 15-11, AND
XCH MPTEMP # SUPERBANK IN BITS 7-5.
MASK LOW10
XCH L # SAVE REL. ADR. IN BANK, FETCH SUPERBITS.
INHINT # BECAUSE RUPT DOES NOT SAVE SUPERBANK.
EXTEND
WRITE SUPERBNK # SET SUPERBANK FOR DATA.
INDEX L
CA 10000 # PINBALL (FIX MEM DISP) PREVENTS DCA HERE
XCH MPTEMP # SAVE 1ST WD, FETCH OLD FBANK AND SBANK.
EXTEND
WRITE SUPERBNK # RESTORE SUPERBANK.
RELINT
TS FBANK # RESTORE FBANK.
CA MPTEMP # RECOVER FIRST WORD OF DATA.
RETURN # 24 WDS. DATACALL 516 MU, SUPDACAL 432 MU
## Page 1075
# THE FOLLOWING ROUTINES ARE IDENTICAL TO BANKCALL AND SWCALL EXCEPT THAT THEY ARE USED IN INTERRUPT.
IBNKCALL DXCH RUPTREG3 # USES RUPTREG3,4 FOR DP RETURN ADDRESS.
INDEX Q
CAF 0
INCR Q
ISWCALL TS L
LXCH FBANK
MASK LOW10
XCH Q
DXCH RUPTREG3
INDEX Q
TC 10000
ISWRETRN XCH RUPTREG4
XCH FBANK
XCH RUPTREG4
TC RUPTREG3
# 2. USPRCADR ACCESSES INTERPRETIVE CODING IN OTHER THAN THE USER'S FBANK. THE CALLING SEQUENCE IS AS FOLLOWS:
# L TC USPRCADR
# L+1 CADR INTPRETX INTPRETX IS THE INTERPRETIVE CODING
# RETURN IS TO L+2
USPRCADR TS LOC # SAVE A
CA BIT8
TS EDOP # EXIT INSTRUCTION TO EDOP
CA BBANK
TS BANKSET # USER'S BBANK TO BANKSET
INDEX Q
CA 0
TS FBANK # INTERPRETIVE BANK TO FBANK
MASK LOW10 # YIELDS INTERPRETIVE RELATIVE ADDRESS
XCH Q # INTERPRETIVE ADDRESS TO Q, FETCHING L+1
XCH LOC # L+1 TO LOC, RETRIEVING ORIGINAL A
TCF Q+10000
## Page 1076
# THERE ARE FOUR POSSIBLE SETTINGS FOR CHANNEL 07. (CHANNEL 07 CONTAINS THE SUPERBANK SETTING.)
#
# PSEUDO-FIXED OCTAL PSEUDO
# SUPERBANK SETTING S-REG. VALUE BANK NUMBERS ADDRESSES
# ---------- ------- ------------ ------------ ------------
# SUPERBANK 3 0XX 2000 - 3777 30 - 37 70000 - 107777 (WHERE XX CAN BE ANYTHING AND
# WILL USUALLY BE SEEN AS 11)
# SUPERBANK 4 100 2000 - 3777 40 - 47 110000 - 127777 (AS FAR AS IT CAN BE SEEN,
# ONLY BANKS 40-43 WILL EVER BE
# AND ARE PRESENTLY AVAILABLE)
# SUPERBANK 5 101 2000 - 3777 50 - 57 130000 - 147777 (PRESENTLY NOT AVAILABLE TO
# THE USER)
# SUPERBANK 6 110 2000 - 3777 60 - 67 150000 - 167777 (PRESENTLY NOT AVAILABLE TO
# THE USER)
# *** THIS ROUTINE MAY BE CALLED BY ANY PROGRAM LOCATED IN BANKS 00 - 27. I.E., NO PROGRAM LIVING IN ANY
# SUPERBANK SHOULD USE SUPERSW. ***
#
# SUPERSW MAY BE CALLED IN THIS FASHION:
# CAF ABBCON WHERE -- ABBCON BBCON SOMETHIN --
# TCR SUPERSW (THE SUPERBNK BITS ARE IN THE BBCON)
# ... ...
# . .
# . .
# OR IN THIS FASHION:
# CAF SUPERSET WHERE SUPERSET IS ONE OF THE FOUR AVAILABLE
# TCR SUPERSW SUPERBANK BIT CONSTANTS:
# ... ... SUPER011 OCTAL 60
# . . SUPER100 OCTAL 100
# . . SUPER101 OCTAL 120
# SUPER110 OCTAL 140
SUPERSW EXTEND
WRITE SUPERBNK # WRITE BITS 7-6-5 OF THE ACCUMULATOR INTO
# CHANNEL 07
TC Q # TC TO INSTRUCTION FOLLOWING
# TC SUPERSW