Atom RGB port?
Posted: Sat Dec 11, 2021 7:31 pm
Here's a slightly cranky one. Does anyone know whether a version of the HogletColourBoardV3 for the Atom was ever ported to the Dragon? Here is a zipped pdf of the Atom schematic:
Having had some spare time to mess around I built one, seeing no immediate reason why it would be grossly incompatible. Having connected the PA,PB,CHB & Y lines directly to the 6847 I did manage to get an output of sorts using an Extron DVS 204, but no signal on a GBS8220. On the Extron the main black-on-green screen appeared towards the bottom right of the screen surrounded by lots of impressionist stuff. The top third of the green-black area was white, the bottom two thirds accurately displayed the black-on-green text. Video electronics isn't my strong point. Am I missing something fundamental that would cause such incompatibility or should it work? I tried with and without 220R & 270R on the RGB side.
At the level of getting a good Dragon display the above may be rendered moot as today I've received an RGB2HDMI board with an Analog interface. Something to play with tomorrow, but it'd be nice to know what was going on with the Atom board though.
Alan
Having had some spare time to mess around I built one, seeing no immediate reason why it would be grossly incompatible. Having connected the PA,PB,CHB & Y lines directly to the 6847 I did manage to get an output of sorts using an Extron DVS 204, but no signal on a GBS8220. On the Extron the main black-on-green screen appeared towards the bottom right of the screen surrounded by lots of impressionist stuff. The top third of the green-black area was white, the bottom two thirds accurately displayed the black-on-green text. Video electronics isn't my strong point. Am I missing something fundamental that would cause such incompatibility or should it work? I tried with and without 220R & 270R on the RGB side.
At the level of getting a good Dragon display the above may be rendered moot as today I've received an RGB2HDMI board with an Analog interface. Something to play with tomorrow, but it'd be nice to know what was going on with the Atom board though.
Alan