Welcome to the Adding a G3 page of the Colour Classic Compendium

Welcome to the Adding a G3 page of the Colour Classic Compendium


Welcome to

Colour Classic Compendium

Presented by Stuart Bell (stuartsmacs at dsl dot pipex dot com)


Adding G3 Power to a Power Colour Classic


Kevin (kevt at tesco dot net) describes what's involved:

To the right are some images of the holes cut in the plastic to allow the Sonnet G3 Cresendo to fit in.

It does not protude much above the level of the plastic ceiling, only 2-3 mm - so cutting space in the plastic drive cradle is sufficient to allow it to fit.

It is important to leave that thinish strand of plastic to act as the stopper preventing the floppy drive from moving back when a floppy is inserted.














One downside is that the logic board will no longer slide out - in fact the whole cage has to be removed and the accelerator inserted or removed through the hole, which is a bit tricky and needs care.


My Sonnet has a 400MHz 1Mb backside cache. I cranked it up to 500MHz using Sonnetclocker 1.2 - and although it ran a bit hotter this was not a problem. I also clocked it down to 300MHz to see if that would effect power significantly - (it didn't seem to make much difference). It wouldn't work at 450MHz though!

I found compatability issues with the Sonnet and System 7.6-8.1 (I think mainly hinging round sound). So for these I think System 8.5, 8.6 are really required, despite what Sonnet claim! (I've no experience of 9.0)


I did something similar with the plastic to allow a Global Village internal modem to fit in. (This may be only 28.8k but it is a proper hardware solution - the Apple ones sap processing power with the modem software.) For this, a corner off the hard drive sled is removed and it only uses three of the mounting screws.


I'm still working on power supply issues.

Above and below: the floppy cradle modified to give clearance to the G3 card.

Above and below: the main CC chassis modified to give clearance to the G3 card.

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