paracomms.asm

大学微型计算机接口技术实验源代码,直接就可以运行,包含了C++和asm代码,比较前面.

;*-------------------------------------------------------*/
;*    ParaCommS.asm(双机并行通信接口实验－发送端程序)         */
;*    并行通信发送程序 Source File                        */
;*    Copyright (c) 2001 by HUST                         */
;*		Modify	 Date	2005.4.10											*/
;*------------------------------------------------------ */

Stack1 segment
         dw  200 dup(?)
stack1 ends
data  segment
message  db'please input char and strike "enter" to send char'   ;系统提示信息
         db 0dh,0ah
         db'strike "esc" to exit ',0dh,0ah,'$'
wait_mes db'receive no ready !if want to exit,please strike ESC',0dh,0ah,'$'
data     ends
code     segment
         assume cs:code,ds:data,ss:stack1
start:   mov ax,data
          mov ds,ax              ;取程序数据段地址
          mov ax,stack1    
          mov ss,ax          
          lea dx,message
          mov ah,09h                    ;显示系统提示信息
          int 21h

main  proc near
          mov  dx,303h
          mov  al,10100000b 
          out  dx,al
delay:    mov  cx,100
lop:      loop lop
          mov  al,0dh                   ;置INTEA=1
          out  dx,al

          mov  bl,01h                   ;发送联络字符
          mov  dx,300h                 
          mov  al,bl          
          out  dx,al

l:        mov  ah,0bh                   ;查有任意键按下？
          int  21h
          cmp  al,0
          je   l                        ;若无键按下，则等待
          mov  ah,01
          int  21h
          cmp  al,1bh
          jz   over                     ;若是ESC键，则退出
          mov  bl,al                    ;保存按键字符→bl


check:    mov cx,200                    ;检测200次
lop1:      mov  dx,302h                 ;检查发送准备好？
          in   al,dx
	       and  al,08h
          jnz  send                     ;若准备好，则转发送         
          dec  cx
          jnz  lop1
          jmp  show                     ;若未准备好，则显示提示信息
send:     mov  dx,300h                  ;发送按键字符
          mov  al,bl 
          out  dx,al
          jmp  l                          ;继续

show:        lea  dx,wait_mes                 ;显示提示信息
          mov  ah,09h
          int 21h
          jmp l

over:     mov  ax,4c00h                 ;程序退出
          int  21h
main  endp
code  ends
           end start