Cristian wrote:So, as confirmed also in the link here above, the DOS 720K format exists.
In any case... no way. I tried disks marked as "DS DD", "Double Side DD", "Single Side DD", Commodore64 and unidentified disks. Also 1.2MB disks. I tried all FLP_TRACK, FLP_DENSITY, FLP_JIGGLE combinations, both with SGoldcard and Trumpcard, Minerva and JM Roms.
I tried different flat cables and differnt PSUs, also the PC PSU. The format process starts normally, you can hear the usual rythmic floppy noises and at the end..... no way!
The same disks are still fully functional when the drive is connected to PC. For some super-odd reason, only one time I managed to read/write with QL a disk previously formatted with Quemulator.
There must be some special additional setting/hack to be done in the drive. Who knows!
Well, on the bright side, I got a fully working 5.25" floppy drive to be connected to my PC. Useful for recover/preserve data from old media (probably for any machine an emulator can manage, e.g. Commodore, Atari...)
It may be that the floppy disk controllers in the QL just cannot handle a 1.2M drive. I don't know if the specs for the chips would tell you.