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Digital-Research-Source-Code/CPM OPERATING SYSTEMS/CPM 3.X/CPM 3.0/SOURCE/prs0mov.asm
Sepp J Morris 31738079c4 Upload
Digital Research
2020-11-06 18:50:37 +01:00

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2.4 KiB
NASM
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VERSION EQU 30
; SID RELOCATOR PROGRAM, INCLUDED WITH THE MODULE TO PERFORM
; THE MOVE FROM 200H TO THE DESTINATION ADDRESS
ORG 100H
STACK EQU 200H
BDOS EQU 0005H
PRNT EQU 9 ;BDOS PRINT FUNCTION
MODULE EQU 200H ;MODULE ADDRESS
LXIM equ 01h
;
db LXIM
ds 2
; lxi b,00 ;set at merge
;
JMP START
; PATCH AREA, DATE, VERSION & SERIAL NOS.
dw 0,0,0,0,0,0,0,0
dw 0,0,0,0,0,0,0,0
dw 0,0,0,0,0,0,0,0
dw 0,0,0,0,0
db 'CP/M Version 3.0'
maclib makedate
@LCOPY ;[JCE] Copyright & build date moved to their own
@BDATE ; files.
db 0,0,0,0 ; patch bit map
db '654321' ; Serial no.
SIGNON: DB 'CP/M 3 SID - Version '
DB VERSION/10+'0','.'
DB VERSION MOD 10 + '0','$'
START: LXI SP,STACK
PUSH B
PUSH B
LXI D,SIGNON
MVI C,PRNT
CALL BDOS
POP B ;RECOVER LENGTH OF MOVE
LXI H,BDOS+2;ADDRESS FIELD OF JUMP TO BDOS (TOP MEMORY)
MOV A,M ;A HAS HIGH ORDER ADDRESS OF MEMORY TOP
DCR A ;PAGE DIRECTLY BELOW BDOS
SUB B ;A HAS HIGH ORDER ADDRESS OF RELOC AREA
MOV D,A
MVI E,0 ;D,E ADDRESSES BASE OF RELOC AREA
PUSH D ;SAVE FOR RELOCATION BELOW
;
LXI H,MODULE;READY FOR THE MOVE
MOVE: MOV A,B ;BC=0?
ORA C
JZ RELOC
DCX B ;COUNT MODULE SIZE DOWN TO ZERO
MOV A,M ;GET NEXT ABSOLUTE LOCATION
STAX D ;PLACE IT INTO THE RELOC AREA
INX D
INX H
JMP MOVE
;
RELOC: ;STORAGE MOVED, READY FOR RELOCATION
; HL ADDRESSES BEGINNING OF THE BIT MAP FOR RELOCATION
POP D ;RECALL BASE OF RELOCATION AREA
POP B ;RECALL MODULE LENGTH
PUSH H ;SAVE BIT MAP BASE IN STACK
MOV H,D ;RELOCATION BIAS IS IN D
;
REL0: MOV A,B ;BC=0?
ORA C
JZ ENDREL
;
; NOT END OF THE RELOCATION, MAY BE INTO NEXT BYTE OF BIT MAP
DCX B ;COUNT LENGTH DOWN
MOV A,E
ANI 111B ;0 CAUSES FETCH OF NEXT BYTE
JNZ REL1
; FETCH BIT MAP FROM STACKED ADDRESS
XTHL
MOV A,M ;NEXT 8 BITS OF MAP
INX H
XTHL ;BASE ADDRESS GOES BACK TO STACK
MOV L,A ;L HOLDS THE MAP AS WE PROCESS 8 LOCATIONS
REL1: MOV A,L
RAL ;CY SET TO 1 IF RELOCATION NECESSARY
MOV L,A ;BACK TO L FOR NEXT TIME AROUND
JNC REL2 ;SKIP RELOCATION IF CY=0
;
; CURRENT ADDRESS REQUIRES RELOCATION
LDAX D
ADD H ;APPLY BIAS IN H
STAX D
REL2: INX D ;TO NEXT ADDRESS
JMP REL0 ;FOR ANOTHER BYTE TO RELOCATE
;
ENDREL: ;END OF RELOCATION
POP D ;CLEAR STACKED ADDRESS
MVI L,0
PCHL ;GO TO RELOCATED PROGRAM
END