MAME Floppy sound emulation

MAME (or its subproject MESS) shows impressive precision for the emulation of arcade and computer systems. One thing that has been slightly out of scope was the emulation of physical phenomena outside of the computer system, in particular the sounds and noises that occur when you operate these systems.

Don't you remember those days when you were listening to your floppy drive? I don't mean those new projects where you play music with a floppy drive, of course. Disk operations took quite some time, compared to the flash drives nowadays. The Commodore 64 was well known for its superb games, but also for its dreadfully slow floppy drive, the C1541. When we dediced to play some of the bigger games, we often put some water in the coffee machine in the meantime, prepared some snacks, or did some other urgent things, and about two minutes later, loading was complete.

Luckily, the TI floppy system was much faster, but when you wanted to work productively, saving long texts or assembling or compiling programs, the floppy operation still was annoyingly slow.