3-1/2" Floppy Market Cornered

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed May 21 18:25:42 2003

> My atari ST, Amiga 500,1200 Use them. DD disk drives were only used for a
> few years so everybody went to HD production (still in use).

2 points :

1) The HP 9114 drive that I mentioned used _original_ DD drives, rotating
at 600rpm. When these drives were designed, the HD disk hadn't been
thought of...

2) Even now, HD drives have a switch to detect the hole in the HD disk,
and one thing this switch does is to change the head write current to
cater for the different coercivity of the DD and HD media.

Have you got _proof_ (either from schematics, or by actually measuring
the write current in an opertation drive) that the write current is the
same for both DD and HD disks in a correctly-functioning name-brand
drive? Becasue I am darn sure it isn't!

-tony
Received on Wed May 21 2003 - 18:25:42 BST