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| MacDVI - OSS Pico 2 based TTL to DVI video converter! |
Posted by: arroz on 2026-05-10 09:58:02
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 |
Posted by: Byrd on 2026-05-11 02:58:07
Thanks Miguel, nice project! Also excellent for testing these boards |
Posted by: kris92 on 2026-07-03 01:23:32
Fantastic, it works perfectly on a Macintosh SE ! I needed a clean RGB to DVI solution. It is just perfect !
Thank you so much for that ! |
Posted by: cheesestraws on 2026-07-03 01:51:10
Aha. I missed this project somehow!
I was looking for something like this a while back, tried to build my own and couldn't get it working properly. Next time I do anything on that project I'll try yours out instead, it looks much better. |
Posted by: iantm on 2026-07-03 06:04:31
This stuff is so amazing!!! I love this community of makers. |
Posted by: arroz on 2026-07-03 09:51:00
I'm glad to hear that! 😊 Did it work on the SE without any modifications? I thought the SE didn't use inverted video like the Plus, but I don't have one to test. |
Posted by: kris92 on 2026-07-03 15:27:37
Just plug and play. Same code, same software. |
Posted by: kris92 on 2026-07-03 15:28:12
Hardware |
Posted by: kris92 on 2026-07-17 12:10:21
Just test my version of an analog board with your HDMI code. I added support for a temperature sensor to control the Macintosh fan. Now waiting for the delivery of a 8.4" inch LCD. |
Posted by: arroz on 2026-07-17 12:57:42
That’s awesome! I want to do something like that, design my own analog board with a MeanWell PSU hanging from it, the pico, speaker, switch etc. I just didn’t have enough time and energy to dedicate to that yet (it would be my first PCB so lots to learn).
Let us know when you have the screen, I would love to see it all working. |
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