Clock Chipping Software Incompatibilities

Fortunately there are very few software compatibility issues that arise from clock chipping Macintosh computers. This is reasonable since we're just running the processor (and some of the subsystems) faster; the software ought to be the same. In the few cases where there are compatibility issues, we have always been able to work around them; some are more elegant than others. The incompatibilities are always the result of a new "mach gestalt" being reported for a clock chipped computer. Several Macs report a different mach gestalt when they are clock chipped to faster (or slower) speeds. Take a look at the table in the Mac Crystal Oscillator Speedup History file if you are curious about a certain base machine.

Sound Manager 3.1
Q605/LC475 with a PPC card
- Q605 (LC475, P475, P476) Speedup w/Apple's PPC card
- Q605 (LC475, P475, P476) Hack for Apple's PPC card by Chad Leigh (chad@xmission.com)
Apple PM7100/66@80, PM8100/100@120, PM8100/110@120, Radius 81/110@120, and Power Computing Power 100 running System 7.5 Update 1.0 need to be patched with the Output Enablers' System 7.5 Updater Patch. The patch is not needed for any of the other clock chipped Apple Macintosh computers described here. Apple has since released System 7.5 Update 2.0 and System 7.5 Update 2.0 Rev 2, and both of which are just fine with clock chipped Macs (and clones); no patches are needed.
MacOS 8.0 Installation Work Around from Michael Santos (michael@alpha.ece.ucsb.edu)
Take a look at PC Compatibility Card for info on a workaround if you have a problem loading the PC Exchange control panel on a PowerMac 6100/DOS.

Marc Schrier

schrier@mac.com