Miguel ArrozWell, the Mac Plus motherboard works! Look at that video signal of the black and white boot pattern! š #RetroApple
Chris EspinosaAnd SCSI works! Itās booting whatever that old SCSI barely spinning disk has! 7.5 something I think. #RetroApple (Apologies for the barking dog outside!)
So hereās the 3 video signals from the Mac Plus: V-sync, H-sync and video itself. We can clearly see the vertical synch impulse (orange), horizontal (green) and video (blue). First image is during a vertical blanking interval (with a global overview on the bottom), second is during a line scan. I forgot to increase the frequency so the gaps in the blue line may be the ? blinking Mac icon or just missing samples. Instrumentation that costed 5 digits is now cheap and DYI! #RetroApple
As curiosity, the logic analyzer is running on an RPi5. The only thing I have that powers it, due to USB-C shenanigans, is the Pi 5 adapter itself, which I was using before to power the PicoPSU that is feeding the Plus board. So now I have the Asus display powering the Mac Plus via USB-C using the same cable that usually powers and carries video from my MacBook Pro, and carrying its video signalā¦ sort of! How weird is that? #RetroApple
Riccardo Mori@arroz If you have soldering capabilities, in the future I may ask you to check on a Mac SE/30 motherboard I own. It looks rather clean at first glance, but the Mac shows the display issue known as āsimasimacā. I donāt have a soldering iron and I have no technical skills when it comes to these things, unfortunately.