Re: A86: Rom Central - Final Questions

To: <assembly-86@lists.ticalc.org>
Subject: Re: A86: Rom Central - Final Questions
From: "Matt2000" <matt2000@gte.net>
Date: Mon, 23 Feb 1998 02:03:29 -0500
Reply-To: assembly-86@lists.ticalc.org


I understand your program, about the extend of what I am willing to do. My
CGI's are in Visual Basic. If I opened up the rom (probably only the first
1024 bytes) in vb as binary, how can I move to the byte position, retrieve
the 3 bytes, and convert that into decimal? I am used to programming
sequential files only with VB.

Also, I guess the retrieval form will be dynamically generated. That way a
hidden input field would be in the html file itself that has the byte
number, so I know which asm program I assigned the user and what to send to
the CGI to compare the results from the user and the calc.

>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.

Follow-Ups:

Re: A86: Rom Central - Final Questions

From: Bryan Rabeler <brabeler@isd.ingham.k12.mi.us>