🚀 go-pugleaf

In article <4407@pegasus.ATT.COM> psrc@pegasus.ATT.COM (Paul S. R. Chisholm;
hey, that's me!) writes:

> A 1.2M disk has exactly twice as many sectors per track, and twice as
> many (narrower) tracks, as a 360K disk.

In article <JACOBS.90Jan19094503@cmos.cs.utah.edu>, jacobs@cs.utah.edu
(Steven R. Jacobs) writes:

> This would mean that the high density disks are 1.44M instead of 1.2M
> would it not?  I believe the high density disks are 15 sectors/track
> while the 360K disks are 9 sectors/track.  This, with twice as many
> tracks on the 1.2M floppies, accounts for the 1.2M size.

The *good* news is, between the two of us, I think we've got it all
figured out.   360K * 2 * (15/9) = 1.2M, and 720K * 2 = 1.44M.  And no
matter how you calculate storage, the coercivity of the high density
disks makes them impossible to format in a low density drive.

> Steve Jacobs  ({bellcore,hplabs,uunet}!utah-cs!jacobs, jacobs@cs.utah.edu)

Paul S. R. Chisholm, AT&T Bell Laboratories
att!pegasus!psrc, psrc@pegasus.att.com, AT&T Mail !psrchisholm
I'm not speaking for the company, I'm just speaking my mind.