SS1 floppy format failure

[Steve M. Burinsky]

I've had friends tell me that they took their SS1 out of the box, popped
in a floppy, and did a "fdformat" with no problems.  When I try it...

% fdformat
Type return to start formatting floppy. <return>
fdformat: FDKIOSCHAR failed, Invalid argument
%

Also, the following is written to /dev/console:
fdioctl: FDKIOSCHAR unsupported transfer rate 0

What am I doing wrong?  It makes no difference whether there is a disk in
the drive or not.

Thanks,
Steve