> ;
> ;   Write the message to the display.
> ;
>          clrf    fsr         ;init message index
> outloop  unbank              ;back here each new message character
>          movf    fsr, w      ;get the index for this character
>          incf    fsr         ;increment the index for next time
>          mcallr  message, reg0 ;get the indexed message char in REG0
>          movf    reg0        ;set Z if this char is null terminator
>          skip_nz             ;got valid message char, not terminator ?
>          goto    loop        ;done writing the message
>          gcall   sendchar    ;send char in REG0 to the display
>          goto    outloop     ;back to do next message character
> ;
> ;********************
> ;
> ;   Local subroutine MESSAGE
> ;
> ;   Return the indexed message character in W.  The 0-N character
> ;   index is in FSR, which is preserved.
> ;
> message  locsub, noregs
>          movlw   low msg     ;get low byte of table start address
>          addwf   fsr, w      ;make table entry address low byte
>          skip_ncarr          ;propagate carry to high address byte
>          incf    pclath
>          movwf   pcl         ;jump the the selected table entry
>
> msg      dt      "Hello"     ;the message string to send
>          dt      0           ;string terminator

I just realized that I changed the subroutine to take FSR as the index (as
documented), but forgot to go back and update the calling code.  Oh well,
that's what I get for letting people see my untested code.  However, the
point of this code was the documentation style, which is still valid.


*****************************************************************
Olin Lathrop, embedded systems consultant in Devens Massachusetts
(978) 772-3129, olin@embedinc.com, http://www.embedinc.com

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