Motorola PowerStack specific notes
The PowerStack machines were the logical replacement
of the
Delta 900 series, after Motorola gave up on the 88K and switched
to PowerPC (around 1994). Their first incarnation
(not to confuse with the PowerStack II which came later, in PC cases)
had the same look as the Deltas,
but are completely different internally. They are no longer VME based,
except for the mass storage bays which use a VME-style connector,
together with a proprietary adapter 96-pin <=> SCSI (SCA or 50-pin).
Unfortunately I have only one of them, and finding additional ones is probably next
to impossible. Additional mass storage boxes can be stacked just as with the
Delta 900.
The base units also contain a PCI bay for floppy and expansion cards.
Over time I have acquired several of the base units and about two mass storage boxes,
which are currently pretty useless due to lack of adapter cards.
The base units are key locked, fortunately one of the boxes came with
a key, and apparently one key fits all, so I immediately replicated it.
I added Cirrus Logic PCI graphics cards which should turn them into entry level
workstations of almost pizza box format. However, the PSU fans are pretty
noisy so I replaced them by quieter ones. Of course cooling now is less effective,
which means the boxes can't be fully loaded with boards anymore.
Loading an OS is another challenge, in principle the PowerStacks
can run AIX, WNT and Linux. None of them are easy to get (specific versions are needed).
Eventually some kind soul provided me with Motorola AIX 4.1.4 which is a very
basic version. One can supplement it with filesets from IBM AIX 4.1.5 media,
but extreme care should be taken because they are only partially compatible.
Hands off hardware drivers, of course, but also some bos.*
filesets from IBM AIX will wreak havoc on a Motorola installation.
More about AIX installation
Over time I found it convenient to abuse one of these boxes
as a RAM tester because their RAM sockets are easy to reach
and the console spits out a RAM test report way before trying the boot devices.
They can take almost any PS/2 memory module from 2MB to 64MB,
be it parity or non-parity. ECC won't work, however.
Pixx
L2 cache board w/ connectors marked in red
Notes
CPU
All units come with a PPC 604 CPU, normally onboard.
Optionally it is supported by a separate L2 cache board
(see picture above). However, I've also seen
CPU and cache combined on a daughterboard plugged into the L2 socket.
RAM
PowerStacks have 4 memory slots which can take up to 4x64MB,
standard 72-pin PS/2 modules, either parity or non-parity.
From experience, the minimum total amount seems to be 8MB.
Gfx
As said, Cirrus Logic PCI graphics cards (GD54xx) will work (cvga0).
Driver filesets are:
devices.pci.cirrus_54xx.rte 4.1.4.2
devices.pci.cirrus_54xx.X11 4.1.4.2
AIX mksysb restore
Apparently the Motorola AIX 4.1.4 mksysb restore
from standalone tape does not work. The original OS CD is needed.
Boot into maintenance mode, and choose "Restore from tape".
Some files, however, aren't restored with their proper file permissions,
but rather with ----------.
Use
ls -l -R | grep "\-\-\-\-\-\-\-\-\-\-"
or similar aids to locate those.
Files related to login should have
-r-sr-xr-x
and those related to LV oder ODM actions
-r-xr-xr-x
Drive slot termination
Apparently, if drive slot #1 isn't used (e.g. by a CD-ROM)
it must be terminated by that special Motorola 96-pin terminator.
Using the debugging monitor
On power-up the system runs the self-test and then
tries to
boot from fw-boot-path.
To abort that sequence
press ESC until you get into a selection menu.
Select item #3 to get into the PPC1bug monitor.
Some commmands are:
IOI # I/O inquiry, scans the SCSI bus and gives controller and device number
IOT;T #
PBOOT <CLUN> <DLUN> # boot from specified controller/device
HE # help, but not very enlightening
From Bill Dennen in comp.sys.powerpc.misc:
"If the FW is PPC1bug then it can handle AIX. The boot command to use
depends on the device id of the CDROM. Use the IOI command to scan the SCSI
bus. The boot command is pboot CLUN DLUN. If the CD is at 3 the command
would be pboot 0 30. Use HE to get command list or minimal documentation."
From Villy Kruse in comp.unix.aix:
>I inherited a Motorola Powerstack that is running AIX 4.1.4. Can
>someone please tell me how to get it to boot from the CDROM so I
>can change the root password?
When power on and the system is about to start selftest, abort
all the steps. You then either end with a menu or a diag prompt
at the menu select 3 to get diag prompt.
Then do iot;t to get a list of SCSI devices, and assuming the
CD is number 60 you do pboot 0 60
You do similar to select any other boot device temporarily.
Misc.
mpsa/b @ eBay
Last updated: 11-Apr-2012, M.Kraemer
L2 cache board w/ connectors marked in red