FYI, Adding some clear & readable photos of the card and the types of monitors you used might help in troubleshooting.

Sanyo's previous machine was a DOS compatible with it's own custom RGB graphics, so it's possible we are not dealing with CGA or EGA.

Also it has been known for random RCA sockets, not distinctively labelled as composite out or video out, to actually be light pen trigger inputs... rare but not unknown.

I’ve edited and added some photos but had to comment to add the last 4

I’ve also added photos of what gets displayed in both screens when I try them

BitWrangler wrote on 2024-04-04, 23:45:

Sanyo's previous machine was a DOS compatible with it's own custom RGB graphics, so it's possible we are not dealing with CGA or EGA.

Also it has been known for random RCA sockets, not distinctively labelled as composite out or video out, to actually be light pen trigger inputs... rare but not unknown.

Would they really add a light pen to an 8088-2?

Do you have access to an oscilloscope ?

I do not, I am really just aiming to find some documentation so I know I have the dip switches correct

The clock crystal is for EGA or MDA frequencies, seems a bit too advanced for just MDA, however, there should be some switch setting that will let it do EGA mono mode on an MDA/Hercules monitor.

BitWrangler wrote on 2024-04-04, 23:45:

Sanyo's previous machine was a DOS compatible with it's own custom RGB graphics, so it's possible we are not dealing with CGA or EGA.

Also it has been known for random RCA sockets, not distinctively labelled as composite out or video out, to actually be light pen trigger inputs... rare but not unknown.

The Hitachi HD46505 have a LPSTB (light pen strobe) input, so not impossible at all. You can check if pin-2 on the D-sub 9-pin is ground. That should indicate the card is CGA, else it is EGA. If it is CGA, can be a CGA composite output and you get no picture because the jumper setting is not correct. Now to find what they do... Try & see ?

Hey fellow countryman ! What a coincidence ! I'm currently working on an old and Juko ST motherboard, and I was actually just searching for documentation for my Sanyo video card... which happens to be exactly the same as yours. It's a CGA compatible card for me. Just so you know, I'm able to display an image via a CINCH/RCA composite cable on my Zenith amber monochrome monitor, as well as on my TV (NTSC mode) through the composite input (it even works with cheap chinese composite CVBS to HDMI adapter). To make it work, switch 1 of DIPSW1 needs to be down. The positions of switches 2, 3, and 4 aren't important (at least in my case).

BitWrangler wrote on 2024-04-05, 15:31:

The clock crystal is for EGA or MDA frequencies, seems a bit too advanced for just MDA, however, there should be some switch setting that will let it do EGA mono mode on an MDA/Hercules monitor.

I don't think the card looks too complex for an early generic CGA/HGC clone, actually, I guess that's exactly what it is. There is 64K of video memory organized as two 32k x 8 memory chips, which is enough for Hercules graphics modes, but would only serve for basic EGA functionality. The card consists of video memory, the HD46505, which is very similar to the standard MC6845 CRTC, a custom bus interface control chips, a custom video memory data formatting chip, a character ROM, a clock generator for HGC operation (CGA operation uses the 14.318MHz from the ISA bus), a PAL, likely for generating the NTSC composite color CGA signal, the LS244 next to the RCA jack as driver for the RGBI output port, a 244 as address driver and a 245 as ISA data driver.

The images of non-syncing composite monitors indicate that the DIP switches are currently set to "monochrome mode", so the card operates at 18.4kHz HSYNC instead of the required 15.6kHz for CGA/NTSC operation.

Huzzah!

A combination of changing the dip switch as per electric_dreams and finding other dip switch settings for a similar model on the retro web produced a working image

Now I just need to wait for the keyboard adapter to arrive and then I can have a look and see what’s in that ST225

BHDellanoy wrote on 2024-04-05, 21:50:

A combination of changing the dip switch as per electric_dreams and finding other dip switch settings for a similar model on the retro web produced a working image

Good news! What were the odds that two guys in France would be searching for the same rare and obscure video card on Vogons on the same day? 😉

Will I need to use the 9-pin for a colour image? Or is it just my monitors that won’t lock on to the signal correctly?

BHDellanoy wrote on 2024-04-06, 20:00:

Will I need to use the 9-pin for a colour image? Or is it just my monitors that won’t lock on to the signal correctly?

In CGA mode (your card obviously is in CGA mode now, if you get an image on your TV), I expect that at least some DIP switch combination will output something that resembles a color video signal on the RCA jack. The color signal will use NTSC, so if you have a monitor that only supports the SECAM or PAL color systems, you will not get a color image. I suppose all flat screen LCD monitors support NTSC, so this is unlikely to be your problem. If the card is correctly configured to generate a color composite signal, it's more likely that the 14.31818 MHz reference clock from the mainboard is not precise enough to generate the NTSC color subcarrier. The original PC and XT mainboard had a trimmer capacitor to tune this frequency, but on later main boards, the crystal is no longer tunable which can cause troubles with certain digital NTSC decoders in LCD television displays.

Try displaying a colored background. If the card outputs color, but the TV doesn't recognize it, you will likely see fine vertical lines, unless the TV suppresses these fine structures even in monochrome mode. If the card suppresses the color information on the RCA jack, all colored backgrounds will look like a solid filled area, no matter how your TV processes the signal. So, if you see vertical lines in solid colored areas, the card is most likely configured correctly for color output, and your only option is to try a different color TV monitor that might be less picky about the color signal. If you don't see vertical lines, there might be a lot of reasons, like the card not outputting color information or the TV suppressing those lines although they are there.