Re: Which order to hook up these drives?

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

Bill Garber <willy46pa@comcast.net> wrote:

> "Jonathan Herr" <dracosilver@wi.rr.com> wrote in message 
> news:hzECe.7504$Rx4.5331@tornado.rdc-kc.rr.com...
> > I have an Apple IIGS, and I have an Apple 5.25 in Disk drive, an Apple
> > Unidisk and two Apple 3.5 in floppy drives.  What order should I hook them
> > up to the machine, (I know the machine works)
> 
> The IIgs's Smartport/Diskport connector can have:
> 
> 2 x 3.5" drives, either Unidisk or Standard 800K
> 2 x 5.25" drives.
> 
> Hook up the 3.5" drives first, then the 5.25" drives.

Some corrections are in order.  (Pardon the pun.)

You can have up to four drives connected (due to signal loading and
power supply restrictions).

Up to two of them can be Apple 3.5 Drives, and up to two of them can be
5.25" drives.  In theory, you could have four UniDisk 3.5s, or two Apple
3.5s and two UniDisk 3.5s.  You might run into access problems with four
3.5" drives, unless you turn off the IIgs RAM disk, as the ProDOS
driver's remapping scheme only supports four drives unless you are
running ProDOS-8 2.0.1 or later.  (5.25" drives are handled
independently.)

Hook up any Apple 3.5 Drives first, then any UniDisk 3.5s, then any
5.25" drives.

If you have a mixture of models of 5.25" drives, their order doesn't
matter.

If you have any SuperDrives, they can be mixed with Apple 3.5 Drives,
but will only function like an Apple 3.5 Drive unless you connect them
to a SuperDrive controller card (Apple II 3.5 Disk Controller Card).

> > and how would I 'ferret' out any drives that might have bad cables?
> > (They might have been roughed up when I dropped some of the stuff, not
> > sure what/how hard it got dropped if it did...)

Make sure the power is off when connecting or disconnecting drives!

I'm assuming your "Apple UniDisk" is a 5.25" drive (Apple made both
5.25" and 3.5" drives with the name "UniDisk").

There are lots of potential failures, so it hard to think of all the
possible combinations which might need to be tested.

Try connecting all the drives at once and seeing if they work.

Your test should include reading and writing a disk in each drive, and
attempting to write to a write protected disk (preferably one you can
afford to lose).  For 3.5" drives, you need to confirm that you are able
to access both sides of the disk: copying a file larger than 6 KB to a
blank disk should be sufficient.

If there is a problem with any drive, then disconnect all of them and
try them one at a time.

Assuming they all work independently, the problem is likely to be
related to passing through or interfering with signals used only by
other drive types, or the drive 2 select signal.  Try just two 3.5"
drives, then just the two 5.25" drives.

If the second 5.25" drive isn't working in combinations, there may be a
fault with the first one's cable (broken drive 2 select signal).  Try
swapping them over and see if the problem goes away.  There could be a
similar issue with the two 3.5" drives, which might prevent the second
3.5" drive working, or either or both 5.25" drives if they are
dasiy-chained.

If you get misleading WRITE PROTECTED errors on 5.25" drives there is
probably a broken write protect signal in the first 5.25" drive's cable.
This pin is also used by 3.5" drives, but for multiple purposes.

-- 
David Empson
dempson@actrix.gen.nz