【汇编】要求利用PC系统机上的8254的0号定时计数器引发的日时钟中断,设计程序
每间隔2s在PC终端屏幕上显示一行字符串'hello',并在后面显示秒数,显示10行后结束.我能弄出字符串,但是秒数怎么弄?
自身程序:
.486
DATA SEGMENT USE16
MESG DB 'hello',0DH,0AH,'$'
OLD1C DD ?
ICOUNT DB 36
COUNT DB 10
DATA ENDS
CODE SEGMENT USE16
ASSUME CS:CODE,DS:DATA
BEG: MOV AX,DATA
MOV DS,AX
CLI
CALL READ1C
CALL WRITE1C
STI
SCAN: CMP COUNT,0
JNZ SCAN
CALL RESET
MOV AH,4CH
INT 21H
SERVICE PROC
PUSHA
PUSH DS
MOV AX,DATA
MOV DS,AX
DEC ICOUNT
JNZ EXIT
MOV ICOUNT,36
DEC COUNT
MOV AH,9
LEA DX,MESG
INT 21H
EXIT: POP DS
POPA
IRET
SERVICE ENDP
READ1C PROC
MOV AX,351CH
INT 21H
MOV WORD PTR OLD1C,BX
MOV WORD PTR OLD1C+2,ES
RET
READ1C ENDP
WRITE1C PROC
PUSH DS
MOV AX,CODE
MOV DS,AX
MOV DX,OFFSET SERVICE
MOV AX,251CH
INT 21H
POP DS
RET
WRITE1C ENDP
RESET PROC
MOV DX,WORD PTR OLD1C
MOV DS,WORD PTR OLD1C+2
MOV AX,251CH
INT 21H
RET
RESET ENDP
CODE ENDS
END BEG
在哪里可以加时间子程序呢?