JGRAHAM2

I’ll try to get that this weekend.

Has anyone seen/used this OS? It allows multiple RAM disks and the ability to boot from a RAM disk. How would this have been used? I used RAM disks to improve performance back in the 80s, but it was just as a second drive used for data reference files. I did find articles referring to the OS. It was on one of my 800XLs stacked on the original ROM. https://www.atarimagazines.com/atariclassics/v2n4/moonlight_workshop.php?fbclid=IwAR2Eo1qz5gvfEF4b8U6moM4C3E3GQHgdz0E5Rik4nEeiZp4NynpuNYu_2W0 https://www.atarimagazines.com/v6n11/empowering8bit.html?fbclid=IwAR0jXsuE8yEUY7PzQgClXUZwrWx7nAvXnYrTEZc7ZpNpNx-__CMAy51cmC0

Just an update. Steve responded very quickly, especially considering the holiday weekend. He is sending a new chip. Again, thanks for the help on troubleshooting the problem. Leech, I hope you get your issue resolved as well.

Thanks!

I have a TL866, so I could reprogram it. I just burned some OS EPROMs for my Ramrod XL 800XL. If you want to look at it, I could exchange with you, or could I pull an image from it and send it? I tried the original 1200XL MMU and it did not behave like the GAL. It just went to a blank screen while the GAL went to the Atari test screen.

I’m happy to say I did not mix them up. The picture attached shows the original MMU (right) and the one I got with the kit. It looks like it was desoldered at some point. My MMU from a spare 800XL board works great.

The MMU was the problem. I didn’t have time this morning to see if I might have just put the old one back in by mistake. Anything is possible. I’ll check that later and post here. Anyway, it is working! Thanks

Yes, I used the MMU that was with the upgrade kit. I could try a spare I have from an 800XL.

I am having a similar issue with a RAMBO 256 upgraded 1200XL and super video 2.1 upgrade as well. It boots into self test and passes the ram test. Holding down option just gets a scrambled screen as does option and select. Replacing the 32 in one board with a RAMROD XL EPROM boots to basic, but the keyboard doesn’t work. Holding option boots to the usual OMNIMON XL memo screen. Holding down option and select brings up OMNIMON XL. The keyboard works in both those modes. Carts work as does FujiNet. Leech, did you give up?

I used the eraser to clean the 3 pads, added a little of the conductive paint to the 2 pads and added the tape as recommended by yorgle. At this point I have a working 1200XL! Thanks to all who responded with suggestions.

The keys do work according to the multimeter, but the resistance must be too high to be read by GTIA. Any idea what it needs to be?

Yorgle, that worked. It has to be the keyboard. Doing the RAM test now. Looking for broken traces.

I found a spare GTIA and replaced it. No difference. I doubt it is the Mylar connections to the PCB because the reset works and it uses the same connector. What they have in common is they connect back to the GTIA. I tested connectivity between the carbon pads and the connector strips and it looks good all the way through, so it shouldn't be a broken trace.

I originally had issues will all keys, but did the keyboard fix. All keys now work except for Start, Option and Select. Reset works. Could this be the GTIA?