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Parallel Part

A

. (

'' ).

/ .

25 . 25

. 8 ( ) .

PCs parallel port had a total of 12 5

3 8bit ports in the processors I/O space.

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Part1:

8 fi.

1 AA .

. 1 ,

. 2 ,

.

dosseg

.model small

.code

start: call test

jmp start

test:

push cx

push ax

push dx

mov ah,06

mov dl,0ffh

int 21h

cmp al,27

je exitcmp al,'1'

je right

cmp al,'2'

je left

cmp al,'0'

je off

pop dx

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pop ax

pop cx

ret

right: mov al,80h

mov dx,378h

lop : out dx,al

ror al,1

call test

call delay

jmp lop

left: mov al,01h

mov dx,378h

loop:out dx,al

rol al,1

call test

call delay

jmp loop

off: mov al,0

mov dx,378h

out dx,al

jmp start

delay: push cx

push ax

push dx

mov cx, 10h

mov dx,0

mov ah,86h

int 15h

pop dx

pop ax

pop cx

ret

exit: mov ah,4ch

int 21h

end

Part2:

8 1

.

.

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dosseg

.model small

.code

x1: mov dx,379h

in al,dx

and al,00001000b

cmp al,08H

je light

mov al,00000000b

jmp end1

light: mov al,11111111b

end1: mov dx,378H

out dx,al

jmp x1

end: mov ah,4ch

int 21h

END