Re: Another Dumb IIgs Question

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

JCarlson <jcarlson1701@gmail.com> wrote:

> I finally got my IIgs up and running on a minimal install floppy (3
> 1/2"). Everything seems to be working okay. However, one thing bothers
> me. I have two GS 3 1/2" disk drives chained together and then one 5
> 1/4" drive at the end of the chain. Everything seems to be alright
> except the 5 1/4" at the end of the chain which flashes its red (read)
> light constantly. As I said, communication between drives seems to be
> working. Its just the flashing light bugs me. Is this normal behaviour
> for this setup?

Yes, it is normal.

The 5.25" drive select light blinks briefly whenever the computer
accesses one of the 3.5" drives.

This is because both the 5.25" and 3.5" drives use the same signal to
select and enable the drive.

The 3.5" drive has an extra signal to tell it that the computer is
accessing the 3.5" drive. When the 3.5" drive detects this, it cuts off
the select signal being passed through to the 5.25" drive. Unfortunately
the 5.25" drive has already seen the very brief select signal, which
makes its LED blink but isn't enough to get the motor started.

The regular blinking is due to Finder polling the 3.5" drive to see
whether you've inserted or removed a disk. It will stop if you are
running any application other than Finder (except while you are in an
open or save dialog box).

-- 
David Empson
dempson@actrix.gen.nz