I have made a basic computer that works perfectly with a standard PAL TV. The video and sync go into a TV modulator and the result is very good.
I now want to output the display into an old Microvitec CUB monitor (as used by the old BBC computers). This monitor is PAL and has TTL inputs for RGB and CSYNC.
I am having trouble getting the sync to work properly. Am I right in assuming that I *should* just be able to take the 'or'd hsync and vsync from a TTL gate and put it straight into the CUB? I'm getting a very bad display, although I can make out the characters on screen. I have also tried inverting the 'or'd CSYNC to make it negative going but that doesn't help either.
Any ideas??
Thanks,
Matthew