remove result prompts, not needed
UI cleanup: deal with overprint for cylinder by using %-3u in printf.
Changed code so that, instead of checking at an instant if the FDC is
still busy, use a timeout loop to wait for the command to finish. This
resolves the "constant resetting of the FDC" issue seen on an old
Toshiba laptop whenever any command completed and then went on to check
interrupt status.