Main acall Init ; initialise
run jnb RI, run ; Wait for RI flag
mov A, SBUF ; Read character
mov P1, A ; move acc to P1
clr RI
sjmp run
.end


Init MOV IE, #00000000B
MOV PCON,#00000000B
mov SCON, #10011100b ;
MOV TMOD,#00100000B
;mov TH1, #254;???????Boud Rate
MOV TCON,#01000000B

ret ; return

That Boud Rate do you want?

;Start of BAUD RATE WIZARD code
MOV TMOD,#20h ;Timer 1 in Auto-reload mode
MOV TH1,#0FDh ;Reload value for 19200 baud @ 11,000 Mhz
SETB TR1 ;Turn on timer 1
MOV A,PCON ;Get current value of PCON SFR
SETB ACC.7 ;Set the SMOD bit
MOV PCON,A ;Update the value of the PCON SFR
;End of BAUD RATE WIZARD code


;Start of BAUD RATE WIZARD code
MOV TMOD,#20h ;Timer 1 in Auto-reload mode
MOV TH1,#0FFh ;Reload value for 28800 baud @ 11,000 Mhz
SETB TR1 ;Turn on timer 1
;End of BAUD RATE WIZARD code


;Start of BAUD RATE WIZARD code
MOV TMOD,#20h ;Timer 1 in Auto-reload mode
MOV TH1,#0FFh ;Reload value for 57600 baud @ 11,000 Mhz
SETB TR1 ;Turn on timer 1
MOV A,PCON ;Get current value of PCON SFR
SETB ACC.7 ;Set the SMOD bit
MOV PCON,A ;Update the value of the PCON SFR
;End of BAUD RATE WIZARD code


;Start of BAUD RATE WIZARD code
MOV TMOD,#20h ;Timer 1 in Auto-reload mode
MOV TH1,#0FDh ;Reload value for 9600 baud @ 11,000 Mhz
SETB TR1 ;Turn on timer 1
;End of BAUD RATE WIZARD code