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



> 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, if you'd been reading you'd know taht teh last checksum is 
used by zshell to find thw rom version, and I've allready posted this 
list and people have made the changes..
if it's to stop saying ROM FAIL, they must also chenges the last byte 
of each other page to $ff..




Rob Taylor MAIL - mailto:rtaylor@ticalc.org 
           WEB  - http://www.u-net.com/~rtaylor/    


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