主程序
0000：2008：  IN   AL,21
     AND AL,FE
     OUT 21,AL
MOV AX,21F3
MOV W[ 0020],AX
MOV AX,00
MOV W[0022].AX
MOV AL,82
OUT 63,AL
MOV AL,34
OUT 43,AL
MOV AL,7C
OUT 40,AL
MOV AL,2E
OUT 40,AL
MOV B[3600],00
MOV B[3601],00
MOV B[3602],00
MOV B[3603],00
MOV B[3604],3A
MOV B[3605],7F
0000：2048:   STI
MOV AL,B[3603]
CALL 2300
MOV AL,B[3604]
MOV AH,01
INT 10
MOV AL,B[3602]
CALL 2300
MOV AH,01
INT 10
MOV AL,B[3602]
CALL 2300
MOV AH,01
MOV AL,B[3604]
INT 10
MOV AL,B[3601]
CALL 2300
MOV AL,0D
MOV AH,01
INT 10
NOP
NOP
CALL 3000
MOV AH,00
MOV AL,B[3601]
MOV B,05
DIV BL
CMP AH,00
JNZ 2048
MOV AL,B[3605]
ROL AL,1
OUT 60,AL
MOV B[3605],AL
CALL 3000
JMP 2048
中断计时程序
0000：21F3  CLI
PUSH AX
MOV AL,34
OUT 43,AL
MOV AL,7C
OUT 40,AL
MOV AL,2E
OUT 40,AL
MOV AL,B[3600]
INC AL
CMP AL,64
JNZ 224F
MOV B[3600],00
MOV AL,B[3601]
INC AL
CMP AL,3C
JNZ 2240
MOV B[3601],00
MOV AL,B[3602]
INC AL
CMP AL,3C
JNZ 2245
MOV B[3602],00
MOV AL,B[3603]
INC AL
CMP AL,18
JNZ 224A
MOV B[3603],00
STI
POP AX
MOV AL,20
OUT 20,AL
IRET
MOV B[3600],AL
JMP 2239
MOV B[3602].A;
JMP 2239
MOV B[3603],AL
JMP 2239

显示程序
0000：2300   MOV AH,00
MOV BL,OA
DIV BL
MOV BL,AH
ADD AL,30
MOV AH,01
INT 10
MOV AL,BL
ADD AL,30
INT 10
RET
延时程序
0000：3000   PUSH AX
MOV CX,0064
MOC AX,0064
DEC AX
JNZ 3007
LOOP 3004
POP AX
RET