Hmm so your case looks like the Atari one? I guess you are sure that this is the original one? It's possible that C-Lab have been producing new motherboards and putting them in old cases (which seems unlikely, your case has a s/n from 10/94) or that the last batch from atari (09/1994) already had th...

Thanks! Are you sure the rev.B isn't a C-Lab MK2/MKX Falcon? The board revision and serial number would imply that.

Could you take a better picture of the B's serial number please?

Btw, is Matthias busy these weeks / months? I've sent him a couple of messages to that email address but haven't heard from him since September 2022 (it was just enquiries but still).

Just an idea, maybe video's vertical synchronisation is slowly drifting away?

Btw this is also a nice demonstration why one has to be careful with selling gear to 'fellow Atarians'. In 2021 you read a heartbreaking story of a sold Falcon from the childhood (so one would be tempted to offer a fair price to the guy), two years later selling it for 3500 UKP.

Hmm, that's really odd. Because from what you describe it seems like the switch to 16 MHz is indeed happening "very soon", i.e. that would be the code I have posted. To me it looks like the issue is the detection of the write itself, not whether the write is happening because it is surely ...

exxos wrote: ↑Tue Jun 27, 2023 11:55 am Oddly the Falcon seems to actually boot up in 8MHz mode until it basically gets to desktop.

That is not correct. TOS does pretty early in the reset handler.

Btw that bit 6 is to check whether the Falcon has been powered up to avoid reinitialising some memory stuff.

Steve wrote: ↑Fri Jun 16, 2023 8:07 pmI use Manjaro, I stopped using Debian based distros, I find Arch based much better

Hilarious!