Need AT&T 3B2/300 EPROM images to replace ones missing in my system

Seth Morabito lists at
Sun Jan 11 12:30:29 CST 2015

* On Tue, Jan 06, 2015 at 09:52:10PM -0800, r.stricklin <bear at> wrote:
> Esteemed listmembers;
> I have started working on restoring a 3B2/300, and right away I've
> discovered the probable cause for the machine's catatonic state.
> Three of the system board EPROMs are missing.

Hello Bear,

I'm very actively working on a 3B2 emulator, so tracking down ROMs was
a primary concern for me. Two very generous list members were able to
dump ROMs for me -- they came from a 310 and a 400, respectively.  The
only difference between the 310 and 400 ROMs appears to be the ROM
serial number, which is encoded as a struct at the top of ROM.
Otherwise they're identical.

I sent them to Al Kossow, so I think the ROM images are probably on
Bitsavers now (or will be soon), but I've also create a GitHub project
for them because I wanted to disassemble and study the ROM contents.
That's here:

The only WE32100 tools I could find were written in pre-ANSI C and
proved very tedious and difficult to port, so I decided to write my
own very crappy WE32100 disassembler instead. I think it was faster
than trying to get the AT&T tools to compile on my mac! Still, that
means there may well be errors in the disassembly, so keep that in

None of these ROMs match your numbers, the ones I have are AAYYC,
AAYYD, AAYYE, and AAYYF. These may work for you, it's worth a shot if
you have some D2764A's lying around.


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