• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

Restoring a Quadra 700 (warning: photo heavy)


Well-known member
By doing oscillator swap - have you run any other issues?

A Quadra 700 which has been clocked differently than it’s stock clock speed will fail to run Apple A/UX operating system. Generally that would be the only drawback.

I believe overclocking it changes the returned Gestalt value, resulting in some oddities like described above. There may be other issues relating to booting or installing certain Mac OS versions as a result.


Well-known member
By doing oscillator swap - have you run any other issues?
Thankfully the biggest issue with everyday operations on a Q700 is just overclocking too much. 33 was my limit before losing features, system stability, but your mileage may vary.

I can't speak to A/UX in depth. I managed to get version 3 completely installed on mine, however I was unable to keep it running after several bootings due to a degenerative spinning HDD malady. I'll be happy to proven wrong with other examples, as I'm simply one witness.

The Gestalt ID problem is more a concern for 040 Macs where a) board resistors' effects on gestalt and frequency/driver value are interconnected (475/605) and b) where board resistors change the gestalt only, but that in turn changes memory timings from ROM and prevents POSTing or booting at higher frequencies (650/800)

I haven't looked into the 63x/64x Macs, but they appear to follow a derivative process that of the 475/605.

MacKilroy is correct though, that these unused gestalt IDs fail in operations where the system enabler doesn't have those IDs.

The gestalt does not change on a 700, as far as I've used it.


Well-known member
This machine is on its way to a new owner in Germany who I'm sure will get lots of enjoyment out of it. :)

My Quadra journey continues with a different machine which I'll be posting about shortly.