Re: Chaining floppy drives to a IIgs

[dempson@actrix.gen.nz (David Empson)]

Michael J. Mahon <mjmahon@aol.com> wrote:

> David Empson wrote:
> 
> >(If you have more than one disk port available, e.g. a disk controller
> >card in addition to the built-in disk port, then you shouldn't have more
> >than about six floppy drives connected in total, counting all disk
> >ports, as it might overload the power supply.)
> 
> I thought that the Disk ][ Controller powered down itself and the drives
> pretty completely.

There isn't much drain on the primary supply for the drive motor (+12V)
but the rest of the drive circuitry may still draw a fair amount on the
+5V rail.  I'm not certain about the nominal limit of six drives in
total - it is probably somewhat higher.  My main point was that you
can't assume that you can have four drives per controller on each of
seven controller cards (or even two drives times seven controller
cards).

> I would not expect any problems unless too many drives are _in use_
> simultaneously.

That would ceratinly cause problems.

-- 
David Empson
dempson@actrix.gen.nz