krweiss@ucdavis.edu (06/13/91)
First, thanks to all that replied to my original posting on this topic. I finally got everything working (kind of!), and I thought I'd post a summary of what happened: My initial problem was that my Mac IIci at home would hang on boot-up, after loading all extensions, but before displaying the desktop. The hang occurred only when virtual memory was turned on. Since I have a third party Quantum 105 in the Mac in question, I assumed the problem was with the disk driver software. To confirm the problem in isolation I did a low-level format with the latest version of the installation software from the vendor and then immediately installed System 7.0. Sure enough, I got the same hang on boot-up. I have an identical IIci system at my work, but with an official Apple 80 Meg Quantum drive. The work system handled virtual memory with no problems. My 105 drive vendor swore up and down that there was nothing wrong with their drivers, and that they had numerous systems running virtual memory under both 24 and 32 bit modes. Just to prove that the problem was the third party drive, I removed it from my machine at home and installed it in my IIci at work. Virtual memory worked perfectly! I then took the 80 Meg drive out of my machine at work and installed it at home. It worked fine, too. My situation was now this: Home: 105 doesn't work, 80 does Work: 105 works, 80 works Pretty weird... So, I did the last thing I could think of. I started removing things from the system at home. Keyboard -- still broken. I pulled 4 megs of RAM out of Bank B. IT WORKED! I began swapping the SIMMs from Bank B into Bank A one at a time, trying to isolate the bad SIMM. All of them worked. I then put the 4 Meg back in Bank B. It still worked -- the problem had gone away. There are only two things I can figure caused the problem in the first place. My best guess is that something in the third party drivers misbehaved when RAM was available in Bank B. When the RAM in Bank B was missing, a default was rewritten, and the system worked fine from then on. The other possibility is that the RAM just wasn't installed properly, but since the 80 Meg drive functioned just fine in the system before I began messing around with it, I doubt this is the case. The only remaining oddity is that it seems to matter what order the files in my Startup Items folder load. If Freehand 3.0 loads first, the system hangs. By renaming the alias with a Z in front, everything works. This was without a doubt the most frustrating problem I've ever encountered. I still don't really know what happened -- all I know is things are working now... BTW, the third party drive is a MacInStor, from Storage Dimensions. Their technical support and service has been excellent, and I recommend their products without hesitation. Ken Weiss krweiss@ucdavis.edu