[Coco] ROMMAX EPROM PROGRAMMER

[Joel Ewy]

coco at yourdvd.net wrote:
> Anyone on the list have any experience with the eetools.com rommax eprom
> programmer? When I try to read a DECB 24 pin ROM as a 2764 it fails, but
> if I set it to 2732, it reads it, but isn't the 2732 4k and the disk
> basic rom 8k? I took the eprom out of my coco 2 controller (ADOS) (24
> pin eprom) and same thing. I am running it on a 500 Mhaz k6-2 in DOS
> mode (windows 98 command prompt) using the pentium version of the
> software. I have other programmers in storage, but to dig for them....
> Any assistance appreciated. - Robert
>
>
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>   
The ROM chips used on the CoCo disk controller are indeed 8K, but in a
24-pin package.  They use a different pin for the high address bit, and
so aren't pin-compatible with the 2764.  Hence the adaptors people have
to wire up in order to stick the much more common 28-pin EPROMs into a
CoCo disk controller.  The Disto controllers (at least the SC-1 & SC-2)
used 28-pin ROM sockets, and can accept the 2764.  The part number you
want to look for for the 24-pin 8K ROMs escapes me now, but I'm sure
there are others on this list who can quote it for you off the top of
their heads...

JCE