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Power-Programmierung
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CD1.mdf
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assemblr
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library
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zenlib
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lst7_1.asm
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Assembly Source File
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1990-02-15
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472b
|
20 lines
;
; *** Listing 7-1 ***
;
; Calculates the 16-bit sum of all bytes in a 64Kb block.
;
; Time with LZTIME.BAT, since this takes more than
; 54 ms to run.
;
call ZTimerOn
sub bx,bx ;we'll just sum the data segment
sub cx,cx ;count 64K bytes
mov ax,cx ;set initial sum to 0
mov dh,ah ;set DH to 0 for summing later
SumLoop:
mov dl,[bx] ;get this byte
add ax,dx ;add the byte to the sum
inc bx ;point to the next byte
loop SumLoop
call ZTimerOff