COM_ADDR EQU 0263H
T0_ADDR EQU 0260H
T1_ADDR EQU 0261H
_STACK SEGMENT STACK
DW 100 DUP(?)
_STACK ENDS
CODE SEGMENT
START PROC NEAR
ASSUME CS:CODE, SS:_STACK
MOV DX,COM_ADDR
MOV AL,35H
OUT DX,AL 						;计数器 T0 设置在模式 2 状态,BCD 码计数
MOV DX,T0_ADDR
MOV AL,00H
OUT DX,AL
MOV AL,10H
OUT DX,AL ;CLK0/1000
MOV DX,COM_ADDR
MOV AL,77H
OUT DX,AL 						;计数器 T1 为模式 3 状态， 输出方波,BCD 码计数
MOV DX,T1_ADDR
MOV AL,00H
OUT DX,AL
MOV AL,10H
OUT DX,AL ;CLK1/1000
JMP $ 								;OUT1 输出频率为 1S 的方波
START ENDP
CODE ENDS
END START