Re: Disk II Phase Question

["Bryan Parkoff" <nospam@nospam.com>]

Eric,

> The head physically has a gap between its poles.  The width of this gap
> determines the width of the track that gets written to the disk.  In the
> Disk II, the width of the head gap is more than 50% of the track-to-track
> spacing, thus making it impossible to reliably store data on two adjacent
> stepper-motor positions ("half-tracks").

    I am not sure that I can understand your comment.  Is it true that head 
writes data on track 5 which it contains valid data while extra unused data 
can be written on track 4.5 and track 5.5.  Extra unused data is like 
invalid bit stream.  How can you draw a picture to explain what head gap is 
for.

Bryan Parkoff