### FILE="Main.annotation"
## Copyright:   Public domain.
## Filename:    INTER-BANK_COMMUNICATION.agc
## Purpose:     Part of the source code for AGC program Retread 50. 
## Assembler:   yaYUL
## Contact:     Ron Burkey <info@sandroid.org>.
## Website:     www.ibiblio.org/apollo/Restoration.html
## Mod history: 2019-06-12 MAS  Recreated from Computer History Museum's
##				physical core-rope modules.

## Page 105

#          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.

                SETLOC          ENDINTFF                        

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
                INDEX           Q                               # POSTJUMP.
                TCF             10000                           

## Page 106
#          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                               

#          THE FOLLOWING ROUTINE OBTAINS THE TWO WORDS BEGINNING AT THE ADDRESS ARRIVING IN A, AND LEAVES THEM IN
# A,L.

DATACALL        TS              L                               
                LXCH            FBANK                           
                LXCH            MPTEMP                          # SAVE FORMER BANK.
                MASK            LOW10                           
                EXTEND                                          
                INDEX           A                               
                DCA             10000                           

                XCH             MPTEMP                          
                TS              FBANK                           # RESTORE FBANK.
                CA              MPTEMP                          
                TC              Q                               

ENDIBNKF        EQUALS