Re: ROM 00 to ROM 01 upgrade

[david@uow.edu.au (David Wilson)]

"Steve Q" <sqnospam@superbio.notrash> writes:

>Hey, long time, no chat...ever get the ROM 01 to boot from AppleShare?

>"Paul Grammens" <grammens@svn.net> wrote in message
>3d63316f@news.svn.net">news:3d63316f@news.svn.net...

>> You could program some eproms, but you'd need an expensive programmer.
>The

>That, we've got.  I just need to know the kinds of chips we'd need.

That is the problem. Apple did not use ROMs with a pinout that is compatible
with any EPROM that I know of.

The 27C010 is the standard 1Mb (128KB) EPROM but it is a 32 pin device
whereas the ROM used in the //gs is a 28 pin chip. If you build an adapter
socket there are only a few lines that need not pass straight through
[+5v and A16 to name two] (and the two 64KB halves of the image will need
to be swapped because the A16 line to the ROM is actually /A16). 
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia