CSEG AT 0000H
LJMP 0030H

CSEG AT 000BH
LJMP ISR_TIMER0_OVF

CSEG AT 0x23
LJMP SERIAL_IN

CSEG AT 0030H
MOV P1, #0
MOV SP,#2FH
MOV R6,#2
MOV R7,#18
LCALL TIM_INIT

END_OF_PROGRAM:
LJMP END_OF_PROGRAM

TIM_INIT:
ANL TMOD ,#0F0H
ORL TMOD ,#02H
MOV TH0 ,#106
SETB TR0
SETB ET0
SETB EA
RET

ISR_TIMER0_OVF:
;18*2*10Hz
DJNZ R7,END_OF_ISR
DJNZ R6,END_OF_ISR
;10hz generalas
MOV R7,#18
MOV R6,#2
;allithato tartomany
DJNZ R5,END_OF_ISR
MOV R5,A
PUSH ACC
MOV A,P2
DEC A
MOV P2,A
POP ACC
END_OF_ISR:
RETI

S_INIT_SERIAL_9600:
MOV      SCON ,#50H         ;Baud  generalas
ANL      TMOD ,#0DFH       ;az  idozitovel
ORL      TMOD ,#20H         ;lehetseges
MOV      TH1 ,#0FDH         ;9600-as baud
SETB     TR1
SETB     TI
RET

SERIAL_IN:
CLR      C
SUBB     A,#30H ;ASCII -->binaris
MOV      B ,#100
MUL      AB
MOV      R2 ,A
LCALL    SERIAL_READ
CLR      C
SUBB     A,#30H ;ASCII -->binaris
MOV      B,#10
MUL      AB
ADD      A,R2
MOV      R2 ,A
LCALL    SERIAL_READ
CLR      C
SUBB     A,#30H ;ASCII -->binaris
ADD      A,R2
RET

SERIAL_READ:
JNB RI,READEND
CLR TI
MOV A,SBUF
READEND:
RET

END