7 Mar
2005
7 Mar
'05
12:01 p.m.
From: "Nico de Jong" <nico at FARUMDATA.DK>
Sent: Monday, March 07, 2005 1:21 PM
From: "Vintage Computer Festival" <vcf at
siconic.com>
I have never heard of any CP/M system with track 0 anywhere but the
beginning of the disk.
CP/M allows for an affset to allow room for the boot tracks and is also
commonly used to partition hard drives.
An optimized CP/M system never accesses the sectors in a physical sequential
method. 8" SSSD disks (3740 formatted) use a logical interleave of 6. This
allows the system to read a sector process the data and read the next
sector. If the sectors were read/written sequentially then you would have
to wait for one complete revolution of the disk to accur first.
Some CP/M systems logically interleave via a data table, other systems
format the sector numbers non-sequentially to do the same thing.
This is done to optimize speed without giving up too much valuable RAM.
Randy
So now that I've got the 8" drive running well on the PC, I am trying to
read 8" CP/M disks.
CP/M disks are a funny bunch. Some formats dont even have
there sector
numbers in sequence; others have track 0 on the center track, others have
it
in the middle, and some have a different number of segmens on different
tracks.
Nico