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Digital-Research-Source-Code/CPM OPERATING SYSTEMS/CPM 2.X/CPM 2.0/pip20pat.asm
Sepp J Morris 31738079c4 Upload
Digital Research
2020-11-06 18:50:37 +01:00

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; pip patch for cp/m 2.0 operation 10/4/79
;
; this patch fixes two errors which occur when
; pip operates under the cp/m 2.0 release:
; (1) the operation pip x=x,x previously
; resulted in a duplicate file when the
; final file size exceeded 16k bytes,
; (2) the sequence of operations
; user 5
; pip b:=*.*
; resulted in a BDOS disk select error
;
;
; pl/m source level changes:
; 0931.1 dest(freel) = 0;
; 1055.1 dest(0) = 0;
; 1057.0 (deleted)
;
; assembly language field patch:
;
org 01f0h ;patch area in pip
dest equ 1dd8h ;location of "dest"
freel equ 12 ;constant offset
open equ 086eh ;local open subroutine
;
p1: ;patch #1 for line 931.1
lxi h,freel
dad b ;hl=.dest(freel)
mvi m,0 ;dest(freel)=0
jmp open ;open file
;
p2: ;patch #2 for line 1055.1
lxi b,dest
xra a ;zero to accum
stax b ;dest(0)=0
ret
;
; code overlays
org 198ch ;line 931.1
call p1 ;patch #1
;
org 1bd5h ;line 1055.1
call p2 ;patch #2
end