ORG 00H
	JMP init

	ORG 23H
	RETI

        ORG 30H
init:
	MOV TMOD, #20H	; Timer 1 mode 2
	MOV TH1, #0FDH	; TH1 = FDH
	MOV SCON, #40H
	SETB TR1	; Start Timer 1

loop:
	CPL P2.5
	ACALL delay
	MOV A, #"H"
	ACALL trans
	MOV A, #"e"
	ACALL trans
	MOV A, #"l"
	ACALL trans
	MOV A, #"l"
	ACALL trans
	MOV A, #"o"
	ACALL trans
	MOV A, #0DH 
	ACALL trans
	MOV A, #0AH
	ACALL trans
	JMP loop

trans:
	MOV SBUF, A
	JNB TI, $
	CLR TI
	RET

delay:
	MOV R3,#1
	MOV R2,#0
	MOV R1,#0
d:	DJNZ R1, d
        DJNZ R2, d
        DJNZ R3, d
	RET

e:
        END