;** Serial port register definitions

SCIBaud equ     $102B   ;serial port baud rate register
SCCR1   equ     $102C   ;SCCR1
SCCR2   equ     $102D   ;SCCR2
SCIstat equ     $102E   ;serial port status register
SCIdata equ     $102F   ;serial port data register

;** MAINE
maine	ldaa  #$01 	;set PC0 & PC1 to be output
	staa   $1007    ;set
	ldaa   #$00	;flag zero
	staa   $1003	;Port C all zero (l & r get instructions)
	ldaa    #$02	;data direction, port d
	staa    $1009
      ldaa    #$32    ;2400 baud when E=2MHz
      staa    SCIBaud ;baud rate reg.
      ldaa    #00      ;1 start, 8 bits, 1 stop
      staa    SCCR1
      ldaa    #$0C    ;xmit and rec. enabled
      staa    SCCR2   ;SCCR2
      ldaa #$55			
	jsr putch 
	ldaa #$03		
	jsr putch 
	ldaa #$ff
	jsr putch 
      bra maine

;** Subprogram putch (put character)
;** Purpose: Sends a character to serial port for transmission
;** Register Usage
;**** On entry: A contains character to send
;**** On exit: all registers as on entry
putch 
        pshb            ;B is used to read SCI status register
pcChkAgn        ldab    SCIstat
        andb    #%10000000      ;mask all but TDRE
        beq     pcChkAgn        ;wait for TDRE to equal 1
        staa    SCIdata
        pulb            ;restore B to entry value
        rts