Re: Quantum powered off drive port

[David.Empson@bbs.actrix.gen.nz]

In article <92323.214645KCR103@psuvm.psu.edu> <KCR103@psuvm.psu.edu> writes:
> I have heard several times that a quantum HD powered off the drive port will
> kill the power supply after a short time.  Well if that is the case, my GS
> should be dead soon, so I would like a good answer.  My GS has a 1MEG CVtech
> memory board, a 1 MEg Ramfast and A Zip 7Mhz/8k.  I have one 5.25 and one 3.5
> drive connect to my Rom 3 GS.  I usually disable the 5.25 by changing the slot
> setting.  If the GS can power up to four disk drives, why would a hard drive
> kill my power supply when I have only two or three total drawing power.

5.25" and 3.5" drives don't use much power, except while the motor is
running.  The IIgs drive port is able to supply enough power to keep
up to 4 disk drives idle, _but_ it can only handle one drive's motor
being active.
The main reason for the four drive limit isn't the power usage of the
drives, but the signal strength of data output by the IIgs - more than
four drives produces too much signal loading (as well as signal
degradation due to cable length).

A hard drive draws a lot more power than a floppy, and does so
continuously.  It's motor is active all the time, and it spins a lot
faster than a floppy drive.  This causes too much loading on the IIgs
power supply.
The power outputs on the drive port are only supposed to be used for
floppy drives.

Switching slot 6 to "Your Card" doesn't "turn off" the 5.25" drive, it
only prevents the computer from accessing it.  The 5.25" drive will
still be using power.
-- 
David Empson

Internet: David.Empson@bbs.actrix.gen.nz    EMPSON_D@kosmos.wcc.govt.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand