Running into a strange issue with 24-bit mode in 7.5.1 - details below:
(1) When wanting to boot into 6.0.8 on the 20SC, the IIfx prompts me to restart in 24-bit mode (no problems here - everything is fine). When I want to go back to 7.5.1, the IIfx remains in 24-bit mode and boots normally with the 20SC still running. However, when I switch off the 20SC and if the IIfx is still in 24-bit mode in 7.5.1, I am greeted with a bomb that tells me "System" illegal instruction (I would get an error 97 if I disabled extensions). The only way to get around this bomb is to either switch on my 20SC or run my Norton Utilities 3.5 CD with the "C" key pressed down
(2) When running Disk First Aid, I'm told that MountCheck found serious errors and that the problem is Overlapped Extent Allocation (with two numbers beside it). Disk First Aid can't repair this so I run Norton Disk Doctor and I find out that some of my fonts have been corrupted (thus far, I have had to delete and reinstall Times, TTY, Oxford & Palatino). Not sure why my fonts are being affected in 24-bit mode, but at least its nothing serious. The internal 1.2GB Quantum drive is quite healthy and the System Folder is in good shape for both partitions
(3) To avoid getting the system bomb and corrupted fonts after finishing in 6.0.8, I enter the Memory control panel in 7.5.1 and manually set it back to 32-bit mode. Afterwards, I restart the IIfx in 32-bit mode with the 20SC still running. Once I've reached the desktop, I then shut down the IIfx, switch off the 20SC, and can boot into 7.5.1 normally without any bomb or font corruption. It's a ridiculous procedure but I can't understand why 7.5.1 is freaking out in 24-bit mode (I thought all of the System 7 releases until 7.6.1 could address 24-bit mode. Thoughts?)
Oh and on an unrelated note the crappy A$$TEC PS this IIfx came with is starting to fail (IIfx chimes then quickly shuts off if the computer was recently powered down - I had the same problem with the other ASTEC unit in my OrangePC IIfx before it made some horrible clicking noises and died for good). Does anyone have a spare working SONY PS they'd like to donate/sell on the cheap?