Project by Scott Baker

Raspbian is not a real-time OS, and the FDC is absolutely intolerant of bytes not being serviced during read or write. If a context switch occurs, then a buffer overrun WILL occur. There are a few tricks that can mitigate this.

The --realtime option will set the process to SCHED_FIFO with maximum priority. This should keep other processes from interrupting it. It also writes -1 to /proc/sys/kernel/sched_rt_runtime_us, which will prevent Linux's mandatory interruption of the process for 50ms every second.

The --pincpu option will pin the process to a particular CPU. In and of itself this isn't useful, but it makes a difference when combined with the isolcpus kernel option.

For maximum performance:

Add isolcpus=3 to /boot/cmdline.txt

Use the --realtime and ``--pincpu 3` options.

It's still not perfect, and writing a floppy driver as a user-mode python program was a pretty silly thing to do, but you can get a failure rate down to a couple of percent, and the automatic retry will take care of that.