Clewer,Brian wrote:
> >        move the byte to W
> >        swap nibbles (swapf)
> >        and with 0x0f
> >        or with 0x30
> >        send that byte
> >
> >        move the byte to W again
> >        and with 0x0f
> >        or with 0x30
> >        send that byte
> This is ok if you use the numbers 0 to 9 but it doesn't work if you
> need HEX values from A to F.
> Any more ideas?

Yeah, you're right.  Good observation.

Okay, time to factor out the nibble to hex ASCII digit stuff into
it's own subroutine ...

hex                             ; convert nibble to ascii hex
        andlw   0x0f            ; keep only the right bits
        movwf   tmp1            ; save it for later
        sublw   0x09            ; subtract from nine
        movf    tmp1,w          ; bring it back (leave carry alone)
        btfsc   status,c        ; test result of subtraction
                                ; (maybe it's btfss, not sure!)
        addlw   0x37            ; adjust to A-F
        return
hex_0
        addlw   0x30            ; adjust to 0-9
        return

byte
        movwf   tmp2            ; save the byte for later
        swapf   tmp2,w          ; grab the high nibble back
        call    hex             ; encode high nibble as hex ascii
        call    send            ; send the byte in w to serial port
        movf    tmp2,w          ; fetch the byte again
        call    hex             ; encode low nibble
        call    send            ; send the byte in w to serial port
        return

I've not tested that.
It's probably wrong somewhere.
I'm a beginner.
Did it work?  ;-)

--
James Cameron                              (james.cameron@digital.com)
Digital Equipment Corporation (Australia) Pty. Ltd. A.C.N. 000 446 800