Re: A86: Rom Central - Database interactivity with rom calls
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Re: A86: Rom Central - Database interactivity with rom calls
You could do something like this: request that the user type in these
so
many bits into the calc (based on the ROM version, in case they're diff.
or
maybe have both handy and just ask the user which one), such as:
:AsmPrgm
:21xxxx <--- Load some # from $0000-$7FFD into hl
:5E <--- ld e,(hl)
:23 <--- inc hl
:56 <--- ld d,(hl)
:23 <--- inc hl
:7E <--- ld a,(hl)
:EB <--- ex de,hl
:CD334A <--- call _disp_ahl
:C9 <--- ret
That would output a decimal # from 0 to 2^24-1, and if you had a copy of
the
rom from that same rom version (you would ask which ver 1st, so that the
person is getting the rom that they already have) you could figure out
easily by getting the 3 bytes from the ROM. You could make it even
tougher
by putting in an "ld a,x\out (5),a" to use any of the rom pages... That
wouldn't take excessively long (actually a little quicker than searching
for
the book) and pretty much insure that the person actually has the calc.
Andy S Johnson wrote:
> How about creating a unique program (with cgi or java or something) that
> displays a few bytes of rom page D that would be checked by the program
> for correctness. This would only be a few bytes long, and still be
> unable to be checked without a calc (or the rom, but then why would they
> be downloading it?)
>
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--
Stephen Hicks
mailto:shicks@mindspring.com
UIN:5453914
AIM:Kupopo1
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