Bulk Erase 8" floppies

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Wed Sep 17 14:26:00 2003

On Wed, 17 Sep 2003, Bryan Pope wrote:
> > But, if you take a look at SS Single sided v DS double sided, the index
> > hole is in a different place!
> In relation to what? How is the index hole in a different place? (I have
> only *seen* 8" floppies and drive, never actually used one)

Examine an 8" diskette. Draw an imaginary line on it, to check for
symmetry - if you were to put the disk in upside down, would the holes
line up? You will find that the write-access slot is symmetrical, but the
write protect notch is NOT symmetrically placed, nor is the position of
the index hole.

IIRC, (unless I just got it backwards!) the index hole of the SINGLE
sided disk is CLOSE to the center line, but the index hole of the DOUBLE
sided disk is visibly substantially further away from the center line.

It is possible to punch additional holes to convert a SS diskette into a
DS, or to convert a SS into a "flippy". The 8" version of the "Berkeley
Microcomputer Flip-Jig" is substantially rarer than the 5.25' version.


Useless trivia: in an episode of the "Computer Bowl" quiz show, NOBODY on
Bill Gates' team had any idea where the write protect notch is on an 8"
diskette!
Hint: where would be the worst place for it to be to cause problems when
the write-enable tab falls off in the drive?

NB: 8" has a write protect notch that can be covered with a write-enable
tab, v 5.25" has a write enable notch that can be covered with a write
protect tab. Some drives (SA455) have jumpers to permit reversing that!
Received on Wed Sep 17 2003 - 14:26:00 BST