Язык Assembler.
Microprocessor simulator 5.0
DB 20
GO:
STI
MOV AL,80
OUT 03
MOV DL,00
BEGIN:
NOP
STI
JMP BEGIN
ORG 20
PUSHF
AND DL,1
JZ START
MOV DL,00
JMP EXIT
START:
CALL 70
MOV DL,01
EXIT:
POPF
IRET
CLI
PUSHF
POPF
IRET
ORG 70
CLI
PUSH AL
PUSHF
IN 03
AND AL,1
JNZ FALL
JMP HOT
FALL:
MOV AL,00
out 03
JMP FIN
HOT:
MOV AL,80
out 03
FIN:
POPF
POP AL
IRET
END