6.asm

几个接口实验的代码。内含：8253、8255、8237、8251、DA0832、AD0809等芯片的实验代码！

stack segment
sta dw 20 dup(?)
top equ length sta
stack ends
data segment
csreg dw ?
ipreg dw ?
flag db 00
mess db'ret',0ah,0dh
     db'8255 pa pb',0ah,0dh,'$'
data ends
code segment
assume cs:code,ds:data,ss:stack

start:
	mov ax,data
	mov ds,ax
	mov dx,offset mess
	mov ah,09h
	int 21h

	cli
	mov dx,213h
	mov al,90h
	out dx,al

	mov ax,350fh
	int 21h
	mov ax,es
	mov csreg,ax
	mov ipreg,bx
	push ds
	mov dx,seg int_proc
	mov ds,dx
	mov dx,offset int_proc
	mov ax,250fh
	int 21h
	pop ds
	in al,21h
	push ax
	and al,7fh
	out 21h,al
	sti

wait_in:
	mov ax,01h
	int 16h
	jz wait_in
	mov dx,ipreg
	mov ax,csreg
	mov ds,ax
	mov ax,250fh
	int 21h
	in al,21h
	or al,10000000b
	out 21h,al
	mov ax,4c00h
	int 21h
int_proc:
	cli
	mov dx,210h
	in al,dx
	mov dx,211h
	not al
	out dx,al
	mov al,20h
	out 20h,al
	sti
	iret
code ends
end start

;线路:
;8259.IRQ7 ------------- 单脉冲
;8255.CS --------------- 210-217H
;8255.A0-A7 ------------ 8个开关
;8255.B0-B7 ------------ 8个LED