Recent content by blturner

I ran the video and logic board tests a few times and everything passed. I also got out one of the other IIx boards and it does not exhibit the same issue like I remembered, so that at least isolates the logic board as the culprit.

Well, at least this makes me feel less crazy! I pulled the batteries, reinstalled and booted into the disk image you provided: glitch remains. I jump started it with no batteries installed: glitch remains. I attempted to manually reset the PRAM from software (opt+cmd+shift open control panel)...

Here it is booted from your disk image:

@David Cook what installer have you used with your Mac II's? I've been using the Legacy Software Recovery CD from https://macintoshgarden.org/apps/apple-legacy-software-recovery-cd, usually installing the system from SheepShaver before moving the disk image onto an SD card for the BlueSCSI.

I had time to look at this again last night. I borrowed a Floppy EMU from a friend and booted from the install disks for Systems 6 and 7. The scramble remains when booted from the floppy on anything other than black & white for grays or colors:

Here are the ROM SIMMs I have: I attempted to reinstall the system tonight a few times, but never got to where the highlight wasn't glitching. Do you think I should be installing the machine-specific software version like in the screenshot below or the "works on any macintosh family" version...

Oh interesting! I will do some more testing tonight. I have two partitions I've been testing with, one is Universal and the other, I believe, was machine-specific. So hopefully that is the culprit.

I took the Toby card and VGA adapter and put them in the IIci and there was no highlight glitching, so it must be something specific to the II(x). I have a 256k and 512k ROM, so I swapped the 256k with the 512k, but no difference.

It's 7.1 from the Legacy Recovery CD image. I also have a 7.5 install on this SD card I booted from just now and the issue is there as well. Could it be the VGA adapter I have? That's the only common denominator besides the display and the BlueSCSI. I'd have to check again, but I don't think...

Here's the result of that test:

I gave that a try just now and the behavior persists.

I think my initial diagnosis was incorrect, the scrambling is happening at 4, 16, and 256. I attempted to record the monitor changes to better illustrate what I'm seeing. Here is the Toby card without the RAM expansion, only supports 16 colors: Here is the Toby card with the RAM expansion...

I've been running in circles attempting to diagnose some garbled text when something is highlighted on screen. At first I assumed it was a RAM issue because I had been reconnecting traces on the problem board, but I've now encountered the issue on two Mac II's and a IIx. Snooper and APD have not...

Happy to report I swapped the oscillator with a new part and it's back in business! Happy #MARCHintosh!

@Fizzbinn kindly mailed me the print he made of this bezel, the results are pretty good! Here are a few shots of the jaz drive with it's original box I got it in. The disk was unopened so I don't believe this drive was ever used, the SCSI cable was still neatly factory wrapped as well. Thanks...