David Thompson wrote:

> ;**********************************************************
> ;* Data tables
> ;**********************************************************

  ; *** Reserve TWO bytes for table_offset ***

> command
          movlw   table_offset    ;Get high 5 bits of table address
          movwf   PCLATH          ;Preload high address
;   PCLATH must be set *in* the subroutine, not *before* it
          movf    table_offset+1,w  ;Transfer low address
          movwf   PCL             ;    to PCL

  ; Data tables (may be anywhere in memory)
> off_hook
>         dt      0x07,"AATDT;",0x0d
> hang_up
>         dt      0x05,"AATH",0x0d
> modem_reset
>         dt      0x05,"AATZ",0x0d
> dummy_dial
>         dt      0x17,"AATM2S07=48DT,xxxxxxxx",0x0d
> ;

  macro   send_command    where
          movlw   HIGH where      ;table high address
          movwf   table_offset
          movlw   LOW where       ;table low address
          call    do_send
          endm

> You can call up one of these modem strings by simply doing this...

          send_command    modem_reset     ;reset string

> ;*********************************************************
> ;* Send modem command string - called with table offset in w
> ;*********************************************************
  do_send
          movwf   table_offset+1  ;Save table offset
          call    command         ;Get first byte (string length)
          movwf   msg_length      ;Save message length
  send_next
          incfsz  table_offset+1,f  ;Increment table offset
          incfsz  table_offset,f  ;   including high byte
          call    command         ;Jump to table
> loop_com
>         btfss   PIR1,TXIF       ;Check if txreg empty
>         goto    loop_com        ;Loop until free
> ;
> wait_CTS                        ;Hardware flow control. CTS norm LOW
>         btfsc   PORTB,CTS       ;Are we clear to send?
>         goto    wait_CTS        ;If CTS = HIGH, modem is busy

> gie_tx
>         bcf     INTCON,GIE      ;Disable interrupts, dammit!
                                  ; But - why?
>         btfsc   INTCON,GIE
>         goto    gie_tx

>         movwf   TXREG           ;Send byte to modem
>         bsf     INTCON,GIE      ;Re-enable interrupts
>         decfsz  msg_length,f    ;Decrement length, if not zero
>         goto    send_next       ;Keep going...
>         return

  E&OE of course ;-)
--
  Cheers,
        Paul B.