Historical relevance of common clone PC was Re: YADA10YR

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Fri Sep 5 17:41:00 2003

> throwing a new one in if it was? I remember my friend's dad had a floppy
> drive alignment gadget, hooked up to an oscilloscope and let you realign the
> heads of your floppy drive. Cost twice as much as a new floppy drive, but if

I still have (and use) devices like that. I have a proper drive exerciser
(not essential -- you can do the same thing with software on the host
machine 99% of the time). You step the heads to the correct track with an
alignemnt disk in the drive and look at the output of the read amplifier
on the 'scope. Then shift the heads until the 2 lobes are the same amplitude.

I also have a little gadget that connects to a PC serial port. Inside is
an ADC and a microcontroller. It's supposed to read the amplitude of said
lobes and the PC will display how far off-track you are. I find this a
_lot_ less convenient than the 'scope, though.

Why do I bother? well, I've had _new_ branded floppy drives that are
marginally aligned. I value my data ... And of course you can't buy new
drives for many classic machines [1] so you have to be able to repair them

[1] And IMHO while you should repair classic computers (they were
designed to work and should be kept working), you should also keep as
many of the original parts as possible. Better to replace a small
component in the drive than the entire drive.

> you fixed one twice, it's paid off :)
>

-tony
Received on Fri Sep 05 2003 - 17:41:00 BST