L format:

An L-format disc has the general format:

<free space map>
<00 filler to sector end>
<root directory>
<rest of disc>

Free space map
--------------

This is a standard OldMap

Root Directory
--------------

This is a 47-entry, 'old' directory, at disc address &200.


L format floppies
-----------------

These are formatted with 256-bytes sectors, 16 to a track. Note that some
disc controllers have difficulty formatting 16 256-byte sectors to a track.

The number of heads in the disc record for an L format floppy is 1, meaning
that the sides are sequenced, not interleaved.
