Mike's PCjr Page

Just curious what would it require to make an HDMI adapter for the Jr to run it on modern TV's and monitors? I've seen homebrew HDMI adapters come out in recent years for other retro computers and consoles. Does anyone know if it would even be possible to convert the video signal of the Jr to something that a monitor with HDMI inputs would be capable of displaying?

No direct experience here, but I have been looking into it and so far unwilling to make the investment.

My best guess is that you will need three components: digital CGA -> analog CGA converter, CGA -> VGA upscaler, and finally VGA -> HDMI converter. Plus a PCjr->9-pin display adapter cable in front of all that.

You can get the first component here (no endorsement, just FYI), and he has advice on the other components:
http://www.bit-c-128.com/buy

An alternative to the first two components (digital CGA -> VGA): https://www.serdashop.com/MCE2VGA

Hopefully someone with direct experience will speak up!

OldComputerGuy wrote:Just curious what would it require to make an HDMI adapter for the Jr to run it on modern TV's and monitors? I've seen homebrew HDMI adapters come out in recent years for other retro computers and consoles. Does anyone know if it would even be possible to convert the video signal of the Jr to something that a monitor with HDMI inputs would be capable of displaying?

i've been experimenting with isa 8-bit video output to DVI-D (not HDMI). you can rework the pcjr motherboard for DVI-D, but it does require some additional PCBs and lots of solder work....

the CGA video on the pcjr is very similar to the original IBM PC CGA video card, and the memory/video upgrade card slot internal to the pcjr can be used as a starting point for the conversion. i discarded the idea of selling a kit for this because it required way too much rework...

https://hackaday.io/project/167089-isa- ... xperiments

Using the memory expansion slot is sort of like how the NESRGB works, and since the CGA out is already digital, I think an external solution like MCE2VGA (but directly to TMDS/DVI/HDMI/whatever) is better. No need to emulate what the PCjr CGA subsystem is doing for a perfect signal since that already comes out the back (well, sync is still analog, but still).