When I bought an NEC PC-8801mkII computer from Japan a few years ago, one of the big problems that I ran into was a lack of video cables. Not only does the PC-8801mkII use an uncommon 8-pin DIN video connector, but it sends digital RGB video (1 bit per channel) at TTL levels and a 15 or 24kHz horizontal sync, which most monitors cannot handle.

This adapter was developed as part of a project for the leaded solder blog. You can see my blog posts about its development at these two links:

• Part 1, a mystical journey to PC88 colour video, covers my initial development of the board.
• Part 2, the last ride of PC88 colour video, covers my changes to fix the backwards pinout.

I decided that I would adapt the "8-pin DIN" problem first. Using this adapter, I could connect the PC-8801mkII to a 24kHz-capable VGA monitor (in my case, an NEC MultiSync 1970NX LCD) and finally view colour video on the system:

This adapter has been serving me well for years, and I have since found out that the pinout is also shared with several other Japanese computers, including the Fujitsu FM-7/FM-8, NEC PC-6001mkII, Sanyo MBC-550/MBC-555, Hitachi Basic Master, and NEC PC-9801UV.

In 2021, I added decoupling caps to the design in order to reduce the incidence of "jailbars" in the output video signal. This did not work as expected, so they should not be populated. Apologies to anyone who had smeary video after installing the capacitors.