How much do 8" Floppies hold?

From: Philip.Belben_at_powertech.co.uk <(Philip.Belben_at_powertech.co.uk)>
Date: Thu Feb 5 10:03:25 1998

Ward (and others) wrote:

> > I keep an 8" floppy disk in the front of my store to amaze people ("Just
> > fold it twice and stick it in your drive...it holds a lot!")
> >
> > Just how much do (did?) they hold? (I'm sure there were different data
> > densities...just a range is all I want!)
>
> If I recall, when IBM first invented the things, they held right about
> 128k, single sided, single density. By the time I first dealt with them
> in the TRS-80 Model 2, they were packing 512k on a single-sided disk.
> Later, the Model 16/6000 Xenix systems were packing 1.25M on a double
> sided disk. Shortly after that, the format died in favor of 5.25HD.
   
Fair summary, except that I'd have said 'the format lives on in 5.25"
HD' - IBM introduced the HD 5.25 inch diskettes to behave as much as
possible like 8 inch ones, even though that meant different magnetic
properties of the oxide from conventional 5.25". And IBM had enough
clout that this displaced the existing 80 track formats right out of the
market. IBM PCs that have HD drives have an 8 inch disk controller
controlling them.

So in summary, an 8 inch disk holds as much as a 5.25 inch one, although
older formats held less...

Now, does anyone know how much a 14 inch floppy held? (it was 14, wasn't
it?) For that matter, who else has ever seen one?

We had a drive at IBM which was bigger than the PC it plugged into. The
disk (I only ever saw the one!) was in a white card envelope instead of
the conventional black plastic one, and the slot where the head went in
was along one of the diagonals, but otherwise I remember blank-all about
it.

Philip.
Received on Thu Feb 05 1998 - 10:03:25 GMT