Running Mac OS 8.5 on A 68k Mac with A PPC Upgrade Card
Running MacOS 8.5 on a PPC upgraded Performa 475 Posted 10/24/1998 Monday morning update (10/26/98) this may be trickier than I thought for some machines. I was in contact with a guy Sunday afternoon who was installing on a Mac IIci w/ TurboPro 601/100. We never did get the right Gestalt mach id number. I also heard from an experienced Mac user who warned of potential problems and constraints: can't boot from CD, more likely to have software incompatibilities, lack of support from Apple or other SW manufacturers. On the positive side, there are two references from those have been able to install on "unsupported" machines. References: 8.5 on PowerBook 540 w/ PPC Upgrade http://www.macnn.com/contributions/osppcinstall.shtml 8.5 on Quadra 700 with PPC Upgrade http://www.asahi-net.or.jp/~gj3y-adc/Q700.html Yes it can be done!! Here's what Apple says in "Installing Mac OS 8.5" on the 8.5 install disk: " Computers with PowerPC processor upgrade cards You cannot use Mac OS 8.5 on a computer with a 680x0 processor that has been upgraded with a PowerPC processor upgrade card." Thanks Apple, now here's how Bob says you CAN do it ... Note: I have only tested this on a PPC upgraded Performa 475. It should work on other 68040/PPC upgrades. It might even work on 68030 TurboPro machines. The same concept may work on G3 upgrades that do not install MacOS 8.5. (This is a work in progress. I'll add hyperlinks when I get more time. Contact me with suggestions at Robertotec@aol.com. ) Prerequisites: 1. It is best to do this on a separate hard drive from your startup drive. You should at least use a volume other than your startup volume. 2. Make sure your drives are backed up. 3. Don't hack anything with a Resource Editor that you can't afford to lose. That usually means to work only on copies of files. 4. If you are using separate volumes on the same hard drive, you will need System Picker or System Switcher to let you switch between Startup Folders. 5. Determine the 'mach' gestalt number of your upgraded system. You can use Techtool or Apple System Profiler to determine this. You will need to convert this number from decimal to hex. Or see Table 1. at the end of this page. Overview 1. Fool the installer into thinking that you are installing on a compatible machine. 2. Install 8.5 on your selected drive. 3. Edit the new 8.5 System file so that it will recognize your computer as a compatible machine. 4. Remove/replace Extensions and Apps that are not compatible. 5. Test out your new system. 6. Update your utilities and apps to 8.5 compatible versions. Details 1. Fool the installer Get a copy of Wish I Were ... and install it on your current system. Restart, set the Wish I Were ... control panel to a system similar to your upgraded system. (I would suggest a 6100/66, 7100/80, or 8100/100.) Restart again. 2. Install 8.5. Install on another drive or at least a separate partition (volume). It should install if you have Wish I Were ... set right. At this point you could try to restart with the 8.5 Startup Volume, just to prove to yourself that it will not work. You will get an error message as soon as the startup screen shows up. 3. Use Resedit or Resorcerer to open the 8.5 System file. Open the "gusd" resource, open resource 1. Locate the values 001F 001C. Replace the 1F with the mach gestalt number for your machine in hex. (For my system it is 104 decimal which converts to 68 hex.) [HELP! What is the second number? The 1C is related to the type of processor. It doesn't seem to correspond to any of the Gestalts that I am aware of. The Q700 used 16 instead of 1 C, though both are PPC601's.] 4. Remove/replace Extensions and Apps that are not compatible. Check the Extensions folder and remove IOmega Driver 6.0.1. I found that to be incompatible. I also found Apple System Profiler 2.1.1 would hang up if I selected "Devices and Volumes". 5. Select the OS8.5 System Folder as the startup folder. Restart with Extensions off (hold down shift key during restart). It should start up in OS8.5. Restart normally and see if you crash. You may have to check out your Extensions by trial and error using Extensions Manager. 6. Check Version Tracker to see what Utilities and Apps you need to update. Table 1. Machine ID: mach Gestalt numbers for Upgraded Machines Hex, Dec, Upgraded Machine Name 68, 104, PowerMac LC 475/Performa 47x (This may also be the gestalt for all 100mhz 601 upgrades.) 69, 105, PowerMac LC 575/Performa 57x 6A, 106, PowerMac LC-Quadra 630/Performa 63x 6B, 107, PowerMac LC 580 74, 116, PowerMac Quadra 700 75, 117, PowerMac Quadra 900 76, 118, PowerMac Quadra 950 77, 119, PowerMac Centris 610 78, 120, PowerMac Centris 650 79, 121, PowerMac Quadra 610 7A, 122, PowerMac Quadra 650 7B, 123, PowerMac Quadra 800 7E, 126, PPC PowerBook 520-540 CE, 206, PowerMac IIci CF, 207, PowerMac IIsi D0, 208, PowerMac IIvi D1, 209, PowerMac IIvx D2, 210, PowerMac IIvm D3, 211, PowerMac IIfx You can contact me at Robertotec@aol.com Bob Rabun
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