Dwayne Reid wrote:
> I posted a set of routines to the list back in March: HEXASCII (hex to
> Ascii), ASCIIHEX (ascii to hex) and UPCASE.  I dug them out when I read
> Eric's challange and like Scott, I'll repost my version of toascii without
> comments.

<snip>
>     skpndc

  Oh yeah! The 'used-once-in-a-blue-moon-digit-carry'.

> I'm looking forward to seeing Eric's UPCASE routine: mine is 10 instructions
> and 11 cycles including the return.

Here's the 6 instruction/7 cycle 'toupper'

toupper
        ADDLW   -('z'+1)
        ADDLW   'z'-'a'+1
        SKPNC
         ADDLW  'A'-'a'
        ADDLW   'a'
        RETURN

It's probably clearer now. The hint has been all but exposed. Roll-over
arithmetic is the key.

BTW. Does anyone have a good explanation why
        ADDLW   -('z'+1)     ==> -('z'+1) evaluates correctly to 0x85
assembles differently than
        ADDLW   -'z'-1       ==> -'z'-1 evaluates incorrectly to 0x87

(I'm using the pre-historic version 3.12.00 of MPLAB)

Scott

--
"The problem with television is not the resolution."
                                 Hugh. F. Frohbach