G3/G4 Upgrades and Speculative Addressing: a follow-up

We have received an assortment of replies to John Rizzo's article posted last time in the G3/G4 Upgrades and Speculative Addressing MacFixIt Extra.

PowerLogix reply The most detailed reply was from Robert Jagitsch of PowerLogix. Robert corrects what he believes to be informational errors in the initial report. His overall contention is that, in any case, this issue is likely to affect only a small number of users and the importance of it has been blown way out of proportion. We have now added the major portion of Robert's statement to the MacFixIt Extra.

XLR8 reply We have also added a related reply from Gary Dailey of XLR8.

Cold boot only? Ken Tarrozi replied to John's comment that zapping the PRAM would cause a problem with certain G3/G4 upgrades only if the zap was from a cold start (thus zapping the NVRAM in addition to the PRAM). John cited an Apple TIL article to support this view. However, Ken writes:

I had purchased an XLR8 G4 card right after they began shipping, and inadvertently ended up proving this myself (painfully). As long as you hold down the Command-Option-P-R keys before you hear the Mac's boot tone, the NVRAM is zapped. It doesn't matter if it's at a cold boot or a warm restart. I've managed to render my machine with the XLR8 G4 card completely unbootable (not even with a CD-ROM or floppy!) every single time I zapped the PRAM right after a regular restart from the Finder. I've verified this with more than one machine.

The only way to get back to where you were is to boot the machine with a processor card that does not use the NVRAM approach for the firmware fix), let the XLR8 extension load (which is what apparently installs the fix in NVRAM, shut down, reinstall the XLR8 G4 card, and boot again.