OSDev.org

I'm trying to read anything from floppy, but I've problem with that. On Bochs and VMWare it works but on real PC not so my guess is that it's something with timing.
After executing command READ or READID in Status Register 0 I'm getting value 0x40 (command sended but execution did not finish) and in Status register 1 value 0x1.
In documentation I've found

If the 82077AA detects a pulse on the IDX pin twice without finding the specified sector (meaning that the diskette's index hole passes through index detect logic in the drive twice), the 82077AA sets the IC code in Status Register 0 to '01' (Abnormal termination), and sets the ND bit in Status Register 1 to '1' indicating a sector not found, and terminates the READ DATA Command.

Does anybody know what can be the reason of such behaviour ?

Ok I've found it. When I set data rate (with CCR register) to 250 kbp/s it's not working, but for 500 kbp/s it's working ok. I guess it's a problem with values that I'm giving to configure and specify command.