TOOLKIT\ZAPUP.ASM  ·  ASM  ·  905 B  ·  1988-09-01  ·  from PersonalComputing_Sep-1988
;============================================================
; ZAPUP         Version 1.0     by Colin J Smith (c) 1988
;
; A program to make a white noise sound - gradually rising
;
; SYNTAX:
;               None
;
;============================================================


first:  cli                     ; disable interrupts
        mov cx,02ffh

begin:  in al,97                ; input port status byte
        mov b[hold],al          ; save port status byte
        mov al,79
        out 97,al
        mov dx,cx

pause:  dec dx                  ; pause loop
        jnz pause
        mov al,b[hold]          ; restore port status byte
        out 97,al
        dec cx
        jnz begin
        sti                     ; enable interrupts
        int 020h                ; exit routine

hold:   db 0

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