Hi!

I got handed a DECstation 5000/125 from a friend (the company he works for
was just throwing the machine out). I installed NetBSD 1.5 on it and
it mostly works - the problem however, is that the machine crashes randomly.

There are three modes of crash:
 1. System drops back to the PROM prompt from which it reboots automatically
    (I set the haltaction parameter to ''r'')
 2. The system crashes, the screen (the graphics adapter in thhis machine
    is at least supported in text mode, didn't check for graphics) remains
    black. Nothing happens.
 3. System crashes, remains totally unresponsive (like 2), and after a
    while even the green power-on light on the front cover goes dark.
    The system seems still to have power, as the diagnostic LEDs are 
    illuminated as well the power-on LED of the transceiver mounted on the
    AUI port. Sometimes (not checked if always) the system mysteriously
    comes back to life and boots - after a long time (once at least 1 hour).

I strongly suspect this to be a hardware problem and I hope to find some
people here with some knowledge of these machines - finding good documentation
for such a machine seems to be quite a challenge unfortunately :-(

At first I considered bad RAM - so I swapped it around with the memory I have
in a dead DECstation 5000/120, but that didn't change anything.

Point 3 leads me to believe that maybe this is a heat problem. But so far
the only really hot part in the system seems to be CPU module.

Hardware inventory according to NetBSD bootup:

<cite>

DECstation 5000/125 (3MIN)
total memory = 16384 KB
avail memory = 12232 KB
using 230 buffers containing 920 KB of memory
mainbus0 (root)
cpu0 at mainbus0: MIPS R3000 CPU (0x230) Rev. 3.0 with MIPS R3010 FPC Rev. 4.0
cpu0: 64KB Instruction, 64KB Data, direct mapped cache
tc0 at mainbus0: 12.5 MHz clock
ioasic0 at tc0 slot 3 offset 0x0
le0 at ioasic0 offset 0xc0000: address 08:00:2b:29:0b:df
le0: 32 receive buffers, 8 transmit buffers
scc0 at ioasic0 offset 0x100000
scc1 at ioasic0 offset 0x180000
mcclock0 at ioasic0 offset 0x200000: mc146818 or compatible
asc0 at ioasic0 offset 0x300000: target 7
px0 at tc0 slot 2 offset 0x0: 3D, 5x1 stamp, 8 plane, 128KB SRAM
Beginning old-style SCSI device autoconfiguration
rz0 at asc0 drive 0 slave 0 DEC RZ25     (C) DEC rev 0700 (SCSI-2)
rz0: 406MB, 1476 cyl, 9 head, 62 sec, 512 bytes/sect x 832527 sectors
rz1 at asc0 drive 1 slave 0 SEAGATE ST51080N rev 0958 (SCSI-2)
rz1: 1030MB, 4826 cyl, 4 head, 109 sec, 512 bytes/sect x 2109840 sectors
rz4 at asc0 drive 4 slave 0 DEC RRD42   (C) DEC rev 4.3d (SCSI-2)

</cite>

NetBSD is installed on the Seagate disk. Neither harddisk came with the
machine, the RZ25 is from my dead DECstation 5000/120 and the Seagate
just came off a newsgroup sale (and was most likely running in some PC
before). The original 2x RZ24 disks are sitting currently in one of my
hardware drawers.

Oh - and I found out that, opposed to the NetBSD documentation about this,
you _can_ mix 2 MB and 8 MB memory modules. I put in 8 2 MB modules first,
then added 2 8 MB modules and ended up with 20 MB, the 8 MB modules
obviously being addressed as 2 MB ones. Not very efficient, but 20 MB
still looked better to me than 16 MB (currently 8x 2 MB is in the
machine - those also cannibalized from the dead one, the 2x 8 MB came
originaly with this DS5000/125).

So, any ideas, tips or pointers where to look?

Thanks,
     Alex.

-- 
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 EMail : als@thangorodrim.de              | WWW : http://www.thangorodrim.de/
 "I think there's a world market for about five computers."
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