add code to eventually enable user selection of sector location, count,
size, etc.
position prompt (incomplete)
Allow editing sector size
allow sector sizes < 256 to be handled properly.
set data transfer to true sector size for < 256 byte sectors
split calculation into unit and data length
properly apply unit length to PIO read and display.
physical vs logical heads
you can enter logical head 0..255 again. fix typo with sector count.
new option to edit physical head
edit sector count too
make it possible to ESC out of data display
automatically reduce sector count if DMA transfer length required
exceeds the DMA buffer.
options to edit MFM and MT settings.