Hi everyone!
Just announcing that a few days ago I published MacDVI, the source and documentation for a small project I've worked on on my free time as part of moving my Mac Plus to an LCD instead of the CRT: https://codeberg.org/arroz/MacDVI This is a DIY project, that anyone can build with a Pico 2 and a level shifter (or a few resistors if you're lucky).
It uses a single Pico 2 to sample the video and outputs it to a 1024x768 DVI (HDMI compatible) screen. Since that resolution is twice the Mac's one (with black bars on top and bottom to compensate for the 384-342 height difference) the scaling is pixel perfect. It works on the 128k, 512k and the Plus. Other B&W compact Macs can probably be made to work as well with a few adjustments in the software, but I don't have any of them to test, unfortunately.
I have written extensive documentation since I would love it to be used as learning material for people getting into electronics and/or restoring these wonderful machines.
As far as I know this is the only converter out there that outputs a digital signal (not VGA), aside from RGBtoHDMI and variants. The motivation was developing something that could be built on a much less expensive, and readily available hardware. Since DispHSTX could do the HDMI part at the resolution I needed, and I knew the Pico could sample signals fast enough (as I have sampled them using the Pico-based Dr. Gusman logic analyzers) it was just a matter of putting all the software together.
It's my first project with a Pico, I loved working on this and almost screamed the first time I saw those PIO state machines sampling the image of my old Plus perfectly.
I hope you find it useful!
Regards,
Miguel Arroz
Just announcing that a few days ago I published MacDVI, the source and documentation for a small project I've worked on on my free time as part of moving my Mac Plus to an LCD instead of the CRT: https://codeberg.org/arroz/MacDVI This is a DIY project, that anyone can build with a Pico 2 and a level shifter (or a few resistors if you're lucky).
It uses a single Pico 2 to sample the video and outputs it to a 1024x768 DVI (HDMI compatible) screen. Since that resolution is twice the Mac's one (with black bars on top and bottom to compensate for the 384-342 height difference) the scaling is pixel perfect. It works on the 128k, 512k and the Plus. Other B&W compact Macs can probably be made to work as well with a few adjustments in the software, but I don't have any of them to test, unfortunately.
I have written extensive documentation since I would love it to be used as learning material for people getting into electronics and/or restoring these wonderful machines.
As far as I know this is the only converter out there that outputs a digital signal (not VGA), aside from RGBtoHDMI and variants. The motivation was developing something that could be built on a much less expensive, and readily available hardware. Since DispHSTX could do the HDMI part at the resolution I needed, and I knew the Pico could sample signals fast enough (as I have sampled them using the Pico-based Dr. Gusman logic analyzers) it was just a matter of putting all the software together.
It's my first project with a Pico, I loved working on this and almost screamed the first time I saw those PIO state machines sampling the image of my old Plus perfectly.I hope you find it useful!
Regards,
Miguel Arroz
