PORTA EQU 40H
PORTB EQU 41H
PORTC EQU 42H
RC EQU 43H
.ORG 1800H
LD A,82H
OUT (RC),A
UTAMA: IN A,(PORTB)
CP 01H
JP Z, NAIK
CP 02H
JP Z, TURUN
LD A, 00H
OUT (PORTA), A
JP UTAMA
NAIK: CALL UP
JP UTAMA
TURUN: CALL DOWN
JP UTAMA
UP: LD A, 00H
UP1: INC A
CALL TUNDA
CP 0FH
OUT (PORTA), A
JP NZ, UP1
RET
DOWN: LD A, 10H
DOWN1: DEC A
CALL TUNDA
CP 00H
OUT (PORTA),A
JP NZ, DOWN1
RET
.ORG 1900H
TUNDA: LD H, 3FH
ULANG2: LD L, 3FH
ULANG1: DEC L
JP NZ, ULANG1
DEC H
JP NZ, ULANG2
RET
.END
