Re: identifying an unknown eprom content

From: didier_at_aida.org
Date: Thu, 27 Aug 2020 13:17:40 +0200
Message-ID: <78e17821-74d3-48e2-d4a7-e26feb3cc53f_at_aida.org>
Hi

I checked for vic20/c64 signature but nothing

the NMI/IRQ/RESET are set to the same location $E002

I've not found any string or it's strangely encoded


On 27/08/2020 13:09, groepaz_at_gmx.net wrote:
> Am Donnerstag, 27. August 2020, 12:48:58 CEST schrieb didier_at_aida.org:
>> I'm trying to identify an eprom with an unknown content
>> I was thinking it was the eprom booting the server (a commodore mother
>> board without screen nor keyboard in an industrial box)
>> (on the commodore we had a network composed of a server and up to 16
>> stations)
>> I have 2 eproms labeled:   pc-central-26-4.bin (8k)  and
>> boot-poste-3.bin  (4)
>> the boot-post-3.bin contains the good content...  [the copyright is
>> present]
>> what I know on the pc-central-26-4.bin:
>> - it's a 8k eprom, starts at $E000, the code starts at $E002 before
>> there are 2 bytes  $00 $BF
>> - it's 6502 code  (seems written by an amateur)
>> - there is some code between $E800 and $E8FF so it's not a 8032
>> - they are writing something around $8000  and also around $0400
>>
>> I was thinking that perhaps it was something for a vic20 or a c64 but
>> I've not really used this 2 machines
>> any idea of what I can do to identify the machine ?
>>
>> I'm thinking to try to check the use of I/O area but I need a better
>> disassembly
> start with posting the binaries perhaps? there are a bunch of people here that
> could help with some educated guessing :)
>
> one thing to always consider is swapped data and/or address lines - which is
> why it helps a lot to have schematics. if you don't, i'd first start looking
> for strings, and make sure they all make sense.
>
> typical c64 or vic20 "kernal" rom should have the hardware vectors in the last
> 6 bytes. typical cartridges have the "cbm80" (or cbmA0 or whatever) signature
> in their first few bytes.
>
> --
>
> http://hitmen.eu                 http://ar.pokefinder.org
> http://vice-emu.sourceforge.net  http://magicdisk.untergrund.net
>
> Life's tough, get a helmet.
>
>
>
>
>


Received on 2020-08-27 14:01:59

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