View Full Version : 8 inch diskettes...

July 25th, 2008, 12:56 AM
I just found a pack of 10 unused 8-inch diskettes. The box is labeled:

p/n: DK-100"
and all the disks are labeled:


All copyprotection stickets are in there (glue has dryed decades ago), and all content labels are inside a sealed plastic bag. I figured the disks are type 1; SS,SD (encoding FM), but does anybody know how many bytes/sector: 128, 256 or 512?

does anybody also know what system might have used disks like that?

July 25th, 2008, 07:51 AM
Hmmm, my first guess would be Wang...

Bytes/sector? Whatever you format, but usually 128. Number of sectors is important though (32?)


July 25th, 2008, 09:51 AM
32 sector, 128 (FM), 256 (MFM) bytes per sector.

Were there ever any (other than the very early IBM jobs with sector holes on the outside edge) 8" HS diskettes with anything other than 32 sector holes? Many 8" drives had circuitry for dividing down the 32 sector pulses to give you 16 or 8 larger logical sectors, but these still operated with 32-sector disks.

I've got a few boxes of the Wangs as well; they were very common.

Dwight Elvey
July 26th, 2008, 06:35 AM
Several systems used hard sectored disk.
Polymophic used hard sectored disk for their
double density (mfm) 8 inch drives.
I have a machine ( Nicolet 1080 ) that is a 20 bit words
machine. It uses 32 hard sectored disk. I partions the disk
into 2 sectors of 16 hard index each with a counter.
There are a number of 5.25 systems that are hard sectored.
Northstar, heathkit, polymorphic and a few others.
There is an electrical advantage to hard sectored. The
controller was simpler and didn't require a PLL and other
special detectors to find special sequences.
When they were able to integrate all the special circuits
into a single chip, hardsectored disk were obsolete.