simple problem...easy answer?

[zoidy]

I am trying to connect my PC to an 8051 then connect that to another 8051 and then to another to a second PC..... so basically i want to send a character from one PC to another through the two boards.

I have two different files, one called transmit.a51 and one called receive.a51, transmit.a51 looks like:

org	8100h

rxbuf:	jnb	RI, rxbuf	;check for received byte from PC
	clr	RI		;clear RI, ready for next character
	mov	A, SBUF		;move character to acc from SBUF
	clr 	p1.0		;set p1.0 to logic 0
	acall 	delay		;call delay
	setb	p1.0		;set p1.0 to logic 1

	clr 	p3.4		;change ports to AUX port

	clr	p1.7		;set p1.7 to logic 0
	acall 	delay		;call delay
	setb	p1.7		;set p1.7 to logic 1
	mov	SBUF, A		;move charcter to SBUF from acc
txbuf:	jnb	TI, txbuf	;send character and test for transmitted
	clr	TI		;clear TI ready for next character
	sjmp 	rxbuf		;jumps back to start of program

delay:	mov	r3, #0ffh
loop1:	mov	r2, #0ffh
take:	djnz	r1,take
	djnz	r3,loop1
	ret

	END

and receive.a51 like this:

org	8100h

	clr 	p3.4		;change ports to AUX port
rxbuf:	jnb	RI, rxbuf	;check for received byte from TAD 1
	clr	RI		;clear RI, ready for next character
	mov	A, SBUF		;move character to acc from SBUF
	clr 	p1.7		;set p1.7 to logic 0
	acall 	delay		;call delay
	setb	p1.7		;set p1.7 to logic 1

	clr	p1.0		;set p1.0 to logic 0
	acall 	delay		;call delay
	setb	p3.4		;change ports to primary port
	setb	p1.0		;set p1.0 to logic 1
	mov	SBUF, A		;move charcter to SBUF from acc
txbuf:	jnb	TI, txbuf	;send character and test for transmitted
	clr	TI		;clear TI ready for next character
	sjmp 	rxbuf		;jumps back to start of program

delay:	mov	r3, #0ffh
loop1:	mov	r2, #0ffh
take:	djnz	r1,take
	djnz	r3,loop1
	ret

	END

when i run them only one character is ent and then the program gets stuck. My problem is the program dosen't loop back to the start and when i try to setb p3.4 at the start of the program it freaks out!!

I think i need to loop the program to go back and check for another character after transmitting or receiving.....not sure though!!

can anyone help me please???