Re: Upgrading GS ROM0->ROM1

[ralphp@prysm.net (Ralph Wade Phillips)]

Hi, Stefan!

In article <4mkqbt$n1h@elbe.do.isst.fhg.de>, walgen@elbe.do.isst.fhg.de
(Stefan Walgenbach) wrote:

> Hi,
> 
> I recently purchsed an Apple IIgs - but it had the unsopported
ROM0-Version. So
> I wanted to upgrade - 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 - I used one with 150ns - I burned the eproim verified it
and put
> it in the GS but it does not work. After showing the blue-screen with the
> copyright and version note it refuses to boot from HD and FD (that is possible
> with the original ROM1 from my friend in my board).
> 
> Can anyone help me?
> 

        AFAIR, the ROMs in the IIgs are 27C512's, same as in the Macintosh Plus.

        Or were they 27C010's?  Memory fails me after so many years ...
But, I'm fairly positive that a 27C256 isn't big enough.

        RwP