I recently upgraded my 1200XL with ClearPic video mod, 5V SIO fix, and OS upgrade to 600XL/800XL compatibility with High Speed SIO and Fast Math patch.
Then I did the video upgrade on my 800XL detailed here: https://atariage.com...rade-for-800xl/
Now I am wondering...
Are there any similar upgrades for the 800? I have mine apart for cleaning and would like to perform any upgrades on it now. I am good with a soldering iron and replacing electronic components and have an EPROM burner.
The 800's video doesn't need upgrading or fixing the way the 800XL and
1200XL's does, IMO. At least, my 800's video is gorgeous, and the 1200XL
video mod (I did the SuperVideo one) makes the 1200XL look almost as
nice as the 800.
The 5V SIO thing is specific to the 1200XL, AFAIK none of the other
Ataris had the current-limiting resistor there.
The OS upgrade is doable. The fast math just replaces the 2K math pack,
you'd use the same code for the 800 as you did for the XLs. Not so sure
about the fast SIO. You want a patched version of the 800 OS, not sure
if this is readily available.
If you want to run the XL OS, it'll take more work (soldering on the OS
module, and possibly soldering to the motherboard too) since it needs
a 16K EPROM. Also the XL OS might need to be patched some to work on an
800. To get this working, you might end up building most of an Incognito
board... better to just buy one, if they're still available.
Hmm, the OS module (personality board) has 3 ROM chips on it. IIRC,
one of these is the 2K math pack, so if you're doing just the fast math,
you'd just be replacing one of the ROMs. Not sure (but someone will know)
what type EPROM to use and whether it's a drop-in replacement or would
require some logic (like a 2600 cart does).
Personally I keep my 800 stock. Maybe if I had another 800, it might
get some upgrades... if I had a 400, it definitely would.