FDC: Data rate
(use fdc_write_drr, which in libdsk version affects DPB)

> Tidy up presentation:
	* menu drawing code (should look like a 16)
	* window title
	* power switch graphic

> Support for other joysticks than key joysticks:
	* Kempston : Done
	* Spectravideo : Done, untested
	* Cascade : Done, except for up/down axis and UI
	* DKTronics

> JOYCE hangs trying to read serial port when no serial data present.
 [Fixed and checked]

> BYTELEN *.Z80 on boot floppy doesn't work; strange disc write errors.
 [Bug in lib765; fixed. I've no idea how it's managed to avoid showing
 up for the last year - perhaps because I rarely write to cpcemu images]

> If I'm feeling really brave: UI for rcpmfs.
