I picked up an 800XL in fantastic condition and added an Antonia CPU/RAM upgrade. Sold it to a friend of mine, and then ended up getting it back :-)
It has pretty fuzzy video though. According to this post:
I'm going to
- REMOVE C56 capacitor (if present). This will dramatically improve sharpness and "edge"-definition.
Lift C54 right-hand side, preferably by inserting an on-off switch (if you want to preserve composite out). This will almost COMPLETELY remove vertical banding (present on Luminance-Y signal).
- Solder Chroma-signal wire from R67/R68 junction, to chroma pin in video port. This will enable the missing chroma-signal on the 800XL (the majority DO NOT have it enabled). No need for pick-up resistor (of any kind).
I'm skipping step 2, as no banding is present; it's just REALLY fuzzy and currently s-video outputs black and white only.
My soldering skill are improving, and I've a shiny new solder station arriving on my day off. I guess I could easily do this with just schematics, but ...
It would be greatly appreciated if someone has pics of these simple finished steps (I like pictorial verification, because I'm pretty new at this stuff still). Any other advice on what to do while I'm in there? Besides the Antonia, all my other work has been on XE models. I put a UAV in my 130XE and if this doesn't work out, I'll probably buy another for the 800XL.