用汇编语言写一段对PC/AT两片8237芯片进行全0全1测试的程序

;对从片编程

MOV AL,04H
OUT DMA+08H,AL
OUT DMA+0DH,AL
MOV AL,0FFH
AA:  MOV BL,AL
MOV BH,AL
MOV CX,08H
MOV DX,DMA
BB:  OUT DX,AL
OUT DX,AL
IN AL,DX
MOV AH,AL
IN AL,DX
CMP BX,AX
JE CC
HLT
CC:  INC DX
LOOP
INC AL
JZ AA
MOV AL,00H
OUT DMA+08H,AL    ;下面是对主片的编程

MOV AL,04H
OUT DMA+0D0H,AL
OUT DMA+0DAH,AL
MOV AL,0FFH
DD:  MOV BL,AL
MOV BH,AL
MOV CX,08H
MOV DX,DMA
EE:  OUT DX,AL
OUT DX,AL
IN AL,DX
MOV AH,AL
IN AL,DX
CMP BX,AX
JE FF
HLT
FF:  INC DX
LOOP
INC AL
JZ AA
MOV AL,00H
OUT DMA+0D0H,AL