Re: Upgrading GS ROM0->ROM1

[dempson@atlantis.actrix.gen.nz (David Empson)]

In article <4mkqbt$n1h@elbe.do.isst.fhg.de>,
Stefan Walgenbach <walgen@elbe.do.isst.fhg.de> wrote:
> 
> I recently purchsed an Apple IIgs - but it had the unsopported
> ROM0-Version. So I wanted to upgrade

This used to be a free upgrade from Apple, but there has been a report
here recently that it isn't free any more (in Canada, at least).

> I got the ROM1-Roms from a friend and they work fine in my GS with
> System 6.0.1 - now I wanted to copy the roms to an eprom - I guess i
> has to be a 27C256

No way.  The IIgs ROM (00/01) is 128KB, but a 27C256 is a mere 32KB.
There is no 128KB EPROM which has 28 pins - they are all 32 pin chips
(the number varies, but 27C010 is what we use at work).

You would have to build an adaptor to get it into the socket.

This is, of course, a blatant violation of Apple's copyright.  You may
be able to buy the version 01 ROM from Alltech Electronics, unless
they have run out.

> I used one with 150ns

I'd go for 120 ns to be on the safe side, but 150 should be fine.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand