Date   : Mon, 18 Mar 2002 09:59:01 -0800
From   : Angus Duggan <angus.duggan@...>
Subject: EPROMs

Chris Johns writes:
>Hiya
>
>This is slightly offtopic..
>
>Does anyone have a facility to erase and burn 2764 EPROMs? I've got some
>I ripped out of an old modem, and I'd like to reprogram them with a DOS
>ROM for my a C= 1541 floppy drive, as the DOS ROM in the drive seems to
>be kaput..

There's an EPROM programmer design for the beeb on my web-site, if you want
to make your own. I've just been looking at what it would take to modify the
design for 27256 EPROMs, and add a daughter board for the beeb to allow
selecting of the high/low halfs as separate 16k EPROMs. I'll modify the
design when I've hacked and tested the programmer.

Reading the datasheets for 27128 and 27256 EPROMs, it appears that you can
erase them by leaving them in direct sunlight for about a week :-) Not that
this is much use in the U.K. (or Seattle, for that matter) at this time of
year!

a.
--
Global Graphics Software Ltd., Seattle, WA 98109, U.S.A.
http://knackered.org/angus