Floppy interface

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Aug 20 01:48:12 2003

> I have read on mailing list the your message that speaks about floppy dis=
> k=20
> and controller :
>
>
> >Read/Write
> >signals,
> >normally using a 26LS31 driver and 26LS32 receiver.

You've trimmed it rather a lot, but that certainly refers to the
ST506-type hard disk interface. The standard floppy interface is all
TTL-level signals.


>
> >But in a sense they're analogue in _time_. In write mode, the >drive
> >writes a flux transition to the disk for every pulse on the >write data
> >line. In read mode, the drive sends a pulse on the read data >line for
> >every flux transition on the disk. There are some restrictions >on
> >allowable frequencies of transisitions, of course.
>
> etc. etc.
>
> I am looking for documentation on the floppy disk interface.I would like=
> =20
> to use a floppy disk in order to save data but I don't know how format=20
> them. Can you help me?

Well, yes, I do have the specs of the standard floppy drive interface
(pinouts, signals, etc), as do many other people here. However, I am not
sure that's what you need.

One thing before I go any further. Unless you're trying to do something
strange (which normally means 'trying to read a {GCR | M2FM | ...} disk')
then I would strongly recomend you use a standard floppy disk controller
IC. If you follow the application circuit for such a chip and wire up the
floppy drive as is shown in said application, then it should all work.

-tony
Received on Wed Aug 20 2003 - 01:48:12 BST