Mystery video card, any idea?

The design is similar to the early PAL video cards.

The 74LS164 captures the monochrome pixels from the input video signal, and the 74LS175 captures the 4-bit color pixels. The output from either of those is fed into the chip marked "KA", which produces an output video signal of some kind.

If the chip marked "KA" is a TCA650 then it's a PAL video card, but it's not clear if that's actually the case.

Maybe it's a simple RGB card circa late-1982?

des1 wrote: The design is similar to the early PAL video cards. The 74LS164 captures the monochrome pixels from the input video signal, and the 74LS175 captures the 4-bit color pixels. The output from either of those is fed into the chip marked "KA", which produces an output video signal of some kind. If the chip marked "KA" is a TCA650 then it's a PAL video card, but it's not clear if that's actually

It's not a PAL video card. The chip marked "KA" is a TTL bipolar PROM.

This is an RGB card. For reference here is my Kaga Taxan RGB card with a similar 6-pin RGB connector:

KAGA.JPG