While I'm not certain, I believe you've got a video problem. The LC 575 under OS 7.5 doesn't recognize the video configuration. I guess OS 8 has more flexibility in this area. Go to the site referred by the previous poster and res-edit the proper settings into 7.5. It worked for me on my "Mystic" upgrade.
This site explains in greater detail the merits of the several types of video mods available if you want 640v480 HiRes/VGA video: http://homepage.mac.com/wtnb/vga.html However, with the VGA (low voltage) video modification you can't go back and use the original CC motherboard. I've also done the VGA (low voltage) video modification on my CC video board and the whole package works like a champ. The LC575 Mystic upgrade is significantly faster than the original CC. With a full set of Video RAM (VRAM) I can even get a 600x800 display (so small print as to be unusable). I've already sold my original CC motherboard. Regards, Dave On Oct 16, 8:11 pm, <[email protected]> wrote: > I am trying to do a "Mystic" upgrade to my Color Classic and bought a LC 575 > logic board off eBay. > > After put in the LC 575 board, this is what happens - > > When I boot from the System 7.5 install diskette, or the System 7.5 Disk > Tools diskette, or the System 7.5 Network Access diskette, or the Norton > Utilities 3.1 Emergency Diskette, all booting halts with the following error > message: > > "Sorry, a system error occurred. > > bus error. > > To temporarily turn off extensions, restart and hold down the shift key. > > Restart" > > However, when I boot from the System 8.1 startup diskette, it boots all the > way up to the desktop without error. > > Can someone explain why this is? > > Xin > > P.S. I zapped PRAM, wiped out (initialized) the hard drive, took out the > network card, and held down shift key when booting - all of which made no > difference. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/ -~----------~----~----~----~------~----~------~--~---
