Re: Help w/ GS Ramdisk and Prodos

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

Ron Fucci <ron.fucci@mindspring.com> wrote:

> what I have found so far is that it appears there is a slot conflict
> between my floppy drives and the ram drive.  if i attach the 3.5 drive
> to the GS and the 5 1/4 drive to the 3.5 drive, i can't access the ram
> drive.

I'd be surprised if it if anything to do with a 5.25" drive.  Although
they are physically connected to the drive chain after any 3.5" drives,
the firmware and operating system regard them as completely independent:
5.25" drives are accessed through slot 6, 3.5" drives and the RAM disk
are accessed through slot 5.

With the RAM disk enabled, you should see the following possible
situations.  I'm assuming Slot 5 is set to "Smart Port", the startup
disk is _not_ set to "RAMDisk", and you don't have a ROM disk of any
kind (they are very rare).

(a) No 3.5" drives connected

/RAM5 is S5,D1

(b) One 3.5" drive connected

3.5" drive is S5,D1
/RAM5 is S5,D2

(c) Two 3.5" drives connected

First 3.5" drive is S5,D1
/RAM5 is S5,D2
Second 3.5" drive is S2,D1

(d) Three 3.5" drives connected (only possible if at least one of them
is a UniDisk 3.5)

First 3.5" drive is S5,D1
/RAM5 is S5,D2
Second 3.5" drive is S2,D1
Third 3.5" drive is S2,D2


For cases (c) and (d), you don't get to see the drives that have been
remapped to slot 2 if you are running ProDOS 1.1.1 or earlier, or if
there is a card in the slot that is treated as a disk controller (e.g. a
RAM card, floppy drive controller, SCSI card, etc.)

In all cases, any 5.25" drives on the daisy chain will appear in slot 6,
as S6,D1 and S6,D2 as appropriate.  This requires slot 6 to be set to
"Disk Port".

> on the other hand, if i attach only one drive to the GS (either one),
> i CAN access the ram drive.  the conflict appears to be the slot 5,2.

If your 5.25" drive really is having this effect, then I suspect your
drive is faulty, but even the worst effect (thinking there is another
3.5" drive connected) shouldn't prevent access to your RAM disk.

Can you please check your Control Panel "Slots" settings.  The relevant
ones should be:

Slot 2: Modem Port
Slot 5: Smart Port
Slot 6: Disk Port
Startup: Scan (or a specified slot number if you prefer).

Also make sure you are using ProDOS-8 version 1.2 or later (or any
version of ProDOS-16 or GS/OS).

> i have noticed other funky behavior for the GS and the floppies.  for
> instance,  the 3.5 drive is supposed to be attached first, then the 5
> 1/4 hung off the 3.5.  when i boot, i would expect the 3.5 drive to be
> 'scanned' first, but the GS boots off the 5 1/4 (?)

That is quite normal.  The scanning mechanism starts at slot 7 and looks
for bootable disks off anything that looks like a disk controller card.
If it can't find a card or bootable disk in the current slot, it steps
down to the next lower slot.  If no bootable disk is found in any slot,
you get the "Check Startup Device" message with the sliding apple.

Assuming you have no card in slot 7 and your control panel settings are
at their defaults, the 5.25" drive is checked first (slot 6), then the
3.5" drive (slot 5).

If you have a SCSI card or other hard drive controller in slot 7, then
it will always be used to boot the machine, unless you change the
startup slot.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand