@Duke, I am running 2.0.4 firmware, and I have a problem running "Roland in Space" from dsk:
http://www.cpcwiki.eu/imgs/0/0e/Roland_in_Space_%28disc%29_%28Amsoft%29.zip I am using DSK A from the zip. With a$="rolspacea.dsk" (I renamed the "Side A" dsk file) , |cd,@a$, run"disc", after the "Are you using a green screen - Y / N " question (Y or N), the cassette interface relais clicks, and then the CPC basically stalls. Usually, after loading, you can hit space and the game starts. However, doesn't work with M4, space doesn't advance the game, and if I hit ESC, the CPC resets. I believe the relais click is a bad sign that somethign goes wrong on the bus. Indeed, Roladn in Space checks if the speech synth is present (SSA1 / DKtronics). It seems that this is causing a headache for M4. Notice that M4 is the only expansion being present, I got this with MotherX4 and LambdaBoard. And on 6128 and 464. Same behavior. I also tried with CPC supplied power to M4 and USB power.
I have no problem loading the same DSK file with DDI3 and speech synthesizer connected, but it "stalls" / resets the CPC with M4 and Roland in Space.
So, something is wrong....
On a second though - maybe it is trying to continue to load from tape?? In that case, how do I prevent that with M4? Sorry if this is a stupid question.