And now, what about a FDC tests suite?
Something that would check the different commands, examining the FDC flags state, the returned values and the timings.
It would be tremendously useful for us emulator authors. The FDC is sadly the most neglected chip at the moment :/
I agreed totally with you, the last weekend i was breaking my head why the original version of Basun (an horrendous game

) doesn't work in emulators, but works perfectly in the real machine.
Well, the problem is when the loader finish to load everything, stop the disk drive motor, send the header to the track 38, wait to receive the acknowledge of this operation (the emulators enter in a infinite loop here, while waiting), restart the motor again, read the track 39 (a dummy read, because this track is a normal formatted track, only has $E5), stop the motor and launch the game.
It looks that the emulators stop immediately the disk drive motor and the program never receive the confirmation of the seek track 38; while in the real CPC take a time, in this time the seek track 38 is made and the FDC signal the operation was made correctly.
.
.
.
Although there is hope

,
arnoldemu has made a lot of work studying the FDC, he's the author of the disk loader of
Batman Begins, and he promise that when he finish a few of his projects, he will publish the sources of the loader and a lot of the secrets of the FDC will be disclosed
PD: While i was writting this, arnoldemu has answered you
PD2: If somebody wants the sources of the memory tester, only ask
