Re: ti-emu: ROM FAIL in TI-85 emulator & other notes


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Re: ti-emu: ROM FAIL in TI-85 emulator & other notes



In article <1.5.4.32.19960902014154.00667bd8@ticalc.org>, David
Ellsworth <davidell@ticalc.org> writes
>Okay, I finally subscribed to the ti-emulator mailing list (something I
>should have done a while ago). Browsing the archive, I saw some messages
>noting that the self test reports "ROM FAIL". This is because the DUMP_ROM
>program skips the last byte of each of the 8 pages in the TI-85's ROM. You
>must change the last byte in each page (or the end of each 16384 block if
>you already concatenated them) to 0xFF. The last byte of the last page is an
>exception; it must be an "anti-checksum", or sort of a "checksum adjuster".
>When you add together *all* the bytes in a ROM dump, the sum should be 0x00.
>The self test checks to see if the checksum actually is 0x00, and if it
>isn't it says "ROM FAIL".
>
>Here are the anti-checksums (in hex):
>
>ROM 2.0   - 2A
>ROM 3.0A  - 57
>ROM 4.0   - 8E
>ROM 5.0   - 5E
>ROM 6.0   - 3D
>ROM 8.0   - 97
>ROM 9.0   - 91
>ROM 10.0  - 35
>
>---
>David Ellsworth
>the ticalc.org project
>davidell@ticalc.org


It works fine now, thanks very much David. 


BTW, could this be put in the emulator documentation??
<pre>
-- 
Richard Guy
Why does a theology professor only open one curtain in the morning..
So he has something to do in the afternoon!!! 
richard@guyy.demon.co.uk
</pre>


References: