Re: 8.5" drive for 11e

[dempson@actrix.gen.nz (David Empson)]

Brian Hammack <brian.hammack@rook.wa.com> wrote:

>  Doug chanted almost zenlike:
> 
>  DC(| There were quite a few 8" drive controllers around for the apple
> 
> I'd heard this before.  :)  My question is, how much data does an 8"
> disk hold?  [5.25" = 140k, 3.5" = 800k]

If I remember right, a standard single sided single density 8" disk (the
original distribution format for CP/M) holds 256K.  Each sector is 128
bytes, 32 sectors per track, 64 tracks per disk.

I'm sure about the sector size and sectors per track, but not about the
total number of tracks.  It might be 80 tracks (320K), but I doubt it.

The CP/M machines we used at work a few years ago also supported double
sided double density disks.  That one I can remember: 17 sectors per
track, 512 bytes per sector, 77 tracks, 2 sides, for a total capacity of
1309K.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand