VDPdigitizer - No Stable Signal

[DorkCentre]

Hi c0pperdragon,

First of all, thank you very much for inventing Lumacode. I’ve already managed to install it in my NES, and now, in combination with the OSSC, I have a great picture again.

Next, I installed the VDPdigitizer in my Master System today. It has one of the first boards from '86/'87 with the VDP 315-5124.

Everything went smoothly so far. However, I’m not getting a stable signal. On the display of the OSSC itself, the values always jump back and forth very fast by a few decimal places. Nothing shows up on the TV; the OSSC stays on its test pattern.

If I connect the RCA cable directly to the TV’s composite input, at least an image appears. But that flickers too and is frayed on the left.

Here are a few pictures of the installation and what it looks like on the OSSC and TV display. As far as I can tell, the soldering is OK. Or did I miss something?

Thanks in advance for checking it out.

Regards,
DorkCentre

[c0pperdragon]

Looking at the picture it seems a bit like there is a solder bridge between the CS and the CLK pin on the VDP. Can you check with a multimeter?

[DorkCentre]

Thanks for the feedback!

Now that I’m looking more closely at the photos, I can see the solder bridge. The multimeter confirmed this. After resoldering the cables, I’m getting a stable image via the OSSC.

Using the VDPdigitizer’s default settings, I got an image with the correct colors right away at a sampling phase of 202. For future reference, these are my OSSC settings for the Master System 1, Board 837-6097, VDP 315-5124.

Thanks again for your help!