After some testing with various DAC amplifiers, I have determined that analog input into the PET Monitor is not very good.
The pattern should fade from black to full green, but instead transitions quickly at about 40 percent.
Fixing this would require changing the actual video drive circuitry, and I won't go that far.
So I guess if I do any kind of GFX board, it will be like the others... high resolution and single shade (digital).
I did test a 720 pixel dot map though, and this Monitor is certainly capable of displaying crisp pixels.
Might try a horizontal resolution of 1024 next, but for that I need a faster microcontroller!
One interesting thing I noted though is if I feed the original PET pixel stream back into the tapped point shown in the last photo, the resulting video is just as good, possibly a little sharper.
Knowing how Commodore would shave every single part from a board, I am surprised that they left 2 extra transistors and a bunch of other passives that seem to do nothing!
Ok, that's it for this thread.
Cheers,
Radical Brad