Hi there,

first, sorry I'm not writing in Polish, but as many of you know, my Polish is piece of shit :)

I have a problem. I made an UltraVideo mod (which is enhanced SuperVideo mod).
http://www.atari8.co.uk/downloads/Ultra … %201.0.pdf

Well, the picture works. But the colour is very noisy, it looks like on untuned old TV.
The S-Video cable is OK, my monitor (LG M1721A) is also OK (works fine with C64 connected trough S-Video).
What I found is there is difference between Ultra- and SuperVideo modifications.
On UltraVideo, the resistor R205 has to be replaced by a diode. On SuperVideo, there should be 75ohm resistor.

But. When I unsolder it (leave the space blank without diode/resistor), the picture goes B/W and is perfectly clean.
When I put here the diode (Ultra), it becomes colourful and awfuly noisy. When there is a resistor (Super) instead of diode, there is a little bit less noise, but still, awful picture.

See the pics.

Again, I did everything from the PDF. Removed modulator, changed resistors, diode, capacitator, checked everything, there is no cold-connection. Cable is OK, connector too. I don't know and this is my last chance.

The computer is 800XE with 320kB and QMEG.

Thank you very much.

Factor6