Disks (was: Re: Generations and Hard/Soft sectoring

From: Brett <danjo_at_xnet.com>
Date: Fri Apr 18 20:36:32 1997

On Sat, 19 Apr 1997, Alexios Chouchoulas wrote:
> On Fri, 18 Apr 1997, Charles P. Hobbs wrote:
> > Generally, I've found that the High Density disks are all but unusable in
> > these older computers/disk drives. . .found that out the hard way when I
> > bought a C128 with a 1751 disk drive, and tried to format some HD disks .
> > ..for a while I thought the disk drive was broken!
>
> I agree here. I've had exactly the same experience with 3.5" disks and
> went through the same hell trying to determine exactly what was wrong.
>
> But it still defies sense. Surely, if the disk has a higher density, it
> should be able to be formatted on a lower density drive. What's so
> different?

Aw come on! Think about it 8-)

The media MUST be able to pack bits closer. (Higher density)
Even at higher spindle speeds you have to flip the dipoles.
You use higher current in the record head to get a bigger signal
 out of the read head.
You do that be using a polished and *harder* (magnetically) medium.
The old soft style head can not successfully record and the read
 head gain is too low the successfully read.

BC
Received on Fri Apr 18 1997 - 20:36:32 BST