I've used this procedure on a PB 520 and 540 both with PPC upgrade cards in them and I've been taken them all the way up to 9.1
I know this is wordy but it's good stuff. An MRP Reader Contribution: Installing 8.5 on PPC-upgraded Macs >From John, October 21, 1998 The first interesting thing is that the packaging and manual disagree on what's supported. The manual indicates that: "You cannot use this version of the Mac OS if your computer has been upgraded with a PowerPC processor card but still has a 68040 (or earlier) processor that is accessed during startup." Since my PowerBook 540 no longer has a 68040 at all I hooked up the CD drive to the PowerBook and launched the installer, and immediately received a notification that my system was not supported by 8.5. Since the manual seemed to indicate that it was supported, I was undetered. I hooked up the PowerBook in SCSI Disk mode to an 8500/200 and proceeded to do a generic install. Upon rebooting, the PowerBook displayed the dread system version not supported message. I fetched a copy of MacsBug and set it to trap on Gestalt, then watched for a call with the 'mach' selector. Sure enough, the first call was to fetch mach. Gestalt returned 7E for my system. According to the Gestalt tables I've seen, 7E is valid for a PowerPC-upgraded 5xx system -- but is not the _only_ valid Gestalt. 7C is also documented as being a 5xx/PPC. Watching the code, sure enough, 7C appears as a supported system in 8.5; 7E is not. Patching the system's table to indicate that 7E was valid worked; the system continued to boot without incident. Eureka! MacOS 8.5 nirvana was mine. But, I was still stuck with a universal install. I switched back to my saved 8.1 System Folder, and back out came the CD, along with a copy of Wish I Were... (available at http://macfixit.pair.com/library/tul/Wish.sit.hqx). Picking the 5xx/PPC setting in Wish I Were (on my 8.1 System Folder) and rebooting resulted in a system which the 8.5 installer was happy to install on. At this point, with 8.5 installed but unpatched, and no MacsBug, it was back to the 8500 to patch the System file. The patch is in the 'gusd' resource. Simply look for the '007C 0024' string and either change the 007C to 007E or pick another pair (I picked the '0080 0024' pair) and change the first number to 007E. I opted to replace the 0080 pair since 0080 is a 5300 and it's very, very unlikely I'd ever use this PowerBook to boot a 5300. In a message dated 10/9/03 10:21:34 PM, [EMAIL PROTECTED] writes: >Message-ID: <[EMAIL PROTECTED]> >From: "The Calypso Organization" <[EMAIL PROTECTED]> >Subject: Re: Putting an new OS on an upgraded 540C >Date: Thu, 9 Oct 2003 20:07:37 +0100 >Is there any way of putting any higher OS than 8.1 on a 540C with a 117mhz >upgrade installed. >OS 8.5 says no and OS 9. doesnt seem to work either? (is there a clever >way?) >Any ideas folks? >Thanks, >Gerald -- PowerBooks is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! | Support Low End Mac <http://lowendmac.com/lists/support.html> PowerBooks list info: <http://lowendmac.com/lists/powerbooks.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/powerbooks%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
