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C/C++ Users Group Library 1996 July
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C-C++ Users Group Library July 1996.iso
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vol_100
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119_01
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ccppat.asm
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Assembly Source File
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1984-07-11
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896b
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23 lines
; This patch causes the CCP of a cp/m 2.x system to look on drive A
; when you are logged into a drive other than A and call for a .COM
; file that does not exist on that drive. Giving an explicit drive
; reference overrides this feature, so that you can always force
; the file to be loaded from a specific drive.
;
msize equ 60 ; set this to your nominal system size
cpmb equ (msize-20)*1024+3400h ; start of CCP in given sys size
;
org cpmb+6dbh
jz patch ; replaces "jz cpmb+76bh"
;
org cpmb+7f2h ; replaces an unused area of NOP's
patch:
lxi h,cpmb+7f0h ; get drive from current command
ora m ; accum was 0 on entry, so this fetches drive
jnz cpmb+76bh ; command has explicit drive...give error
inr m ; force explicit reference to drive A
lxi d,cpmb+7d6h ; we need de set up when we
jmp cpmb+6cdh ; re-enter ccp
;
end
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