Re: CP/M disk format question

["Bill Garber" <willy46pa@comcast.net>]

"Paul Schlyter" <pausch@saaf.se> wrote in message news:g588c2$28ac$1@merope.saaf.se...
> In article <48779f9e$0$17148$742ec2ed@news.sonic.net>,
> Andy McFadden  <fadden@fadden.com> wrote:
> >All of this is in the context of Apple II CP/M on a 5.25 floppy.
> >
> >CP/M disks use 1K blocks, and have a directory starting at block 12 (track 3
> >on a 5.25" disk).  The first 3 tracks are reserved for the boot image.  That
> >leaves 140K - 12K = 128 blocks.
> 
> All of those quantities are actually configurable - their values are
> stored in the DPB (Disk Parameter Block) in the BIOS, where each disk
> has its own DPB.
> 
> I hooked up 80 track DSDD disks to my Apple II in the 80's and made
> all of the disk into a 640K CP/M disk volume.  Then I had to make the
> CP/M blocks 2K large, since a CP/M disk with 1K blocks cannot be as
> large as 640K.


Paul, 

I read this somewhere before. 
Is/was it documented on your site at one time? 

Bill Garber from GS-Electronics
http://www.garberstreet.com