3.5" drives (720,1.44 or 2.88)

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Tue Aug 5 16:20:25 2003

> But 720K, 1.4M, and 2.8M are all 80 track, at 135 tracks per inch.

Err, strictly they're all 160 track. What you meant, I guess, is 80
_cylinders_.

I have the docs for some 5.25" floppy drives which correctly describe the
40 cylinder DS and 80 cylinder SS models as both having 80 tracks. That
confuses a lot of people :-)

> With the exception of some of the rarer early Sony drives (600RPM), and

Rare? I think that's the most common sort of 3.5" drive round here (maybe
because I'm an HP addict)...

Incidentally, apart from the 'normal' full-height 600 rpm drive that's
used in older HP disk units, in the Apricot, and so on, there's also a
more normal sized one with a 34 pin connector (and maybe a separate 4 pin
power connector, although the version I have has the power on the
odd-numbered pins of the data cable). This is used in the HP9114B, 9153,
etc units. One interesting feature of this drive is that many parts
interchage with the Apple 800K drive (the head assembly, stepper, many
mechanical bits, the motor drive ICs, the analogue ASIC, etc). There
even seems to have been an option to add motorised ejection to this drive.

> the early Mac drives, ALL of the 3.5" drives are 300 RPM.

And AFAIK _all_ 1.44M drives are 300rpm. I've never seen a 600rpm version.

-tony
Received on Tue Aug 05 2003 - 16:20:25 BST