FW: Writer wants to quote users

From: Pete Turnbull <pete_at_dunnington.u-net.com>
Date: Sat Jul 25 03:08:05 1998

On Jul 24, 18:02, Max Eskin wrote:
> So, can a standard XT controller be used for 8" drives?

You need a little adapter to shuffle the signals from the 34-pin connector
to a 50-pin connector, but usually that's all. The data rate for an 8" DD
(MFM) disk is the same as for a 3.5" HD (also MFM) disk. If you want to
use 8" SD (FM) disks, you may need to add a jumper to the controller, as
not all XT controllers can handle single-density.

> So does this mean 1.2MB floppies use a lower bps than 360K disks?
> Which controllers were these? I ought to watch out.

Other way round. The 360K disks (better called 40-track double-sided)
normally run at 300 rpm and (for MFM/double density) use a data rate of 250
bps. Before HD disks, 80-track disks were made the same way. Most HD
drives, though, switch to 360 rpm and use a data rate of 300 bps (or 600
bps in HD mode). Some of those HD drives can be switched between 300/360
rpm by the signal on pin 1 of the interface, which is used for DD/HD

Pete						Peter Turnbull
						Dept. of Computer Science
						University of York
Received on Sat Jul 25 1998 - 03:08:05 BST

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