Subject: Re: Randomly crashing DECstation 5000/125 with NetBSD 1.5
To: None <>
From: Alexander Schreiber <>
List: port-pmax
Date: 02/19/2001 01:35:18

On Mon, 12 Feb 2001 wrote:

> On 12 Feb, Alexander Schreiber wrote:
> > the problem however, is that the machine crashes randomly.
> [...]
> > I strongly suspect this to be a hardware problem 
> Apply the "Kreidler" repair method: Disasemble the whole machine and
> reasemble it. Press in all socketed chips. Remove any dust. This often
> solves obskure hardware faults of old machines. 

This remains to be done. So far I restored the original memory configuration
the machine had when it came to me and I removed and reinstalled the
CPU module. I also added more hardware to it: a PMAD-A Ethernet board,
now occupying TC slot 0. Running test from the PROM found nothing to
complain (except a missing cable connection for the network card, but thats
ok -  the AUI port of is currently not in use).

During the messing around with the system it occured to me that the cache
chips on the CPU module get rather hot - too hot to touch in fact. Could
it be that due to very hot cache chips the probability of a random bit 
flipping there increases seriously? I know that the AMD K6 CPU doesn't like 
overheating at all - it first produces strange errors and then stops 
working altogether (until cooled down). The temperature of the room where
the DECstation is running is about 30 degrees Celsius ... 
I gonna add a fan to the machine in the next few days to blow cold air
directly at the CPU module (and remove and reseat the graphics board while
the machine is open), maybe that will help. Currently the machine stays
up usually a few hours and the crashes, but sometimes it crashes during 
boot (after it has crashed before).

I would really like to put this machine to productive use, but that
requires reliable operation. My idea is to use it as a NATing firewall and
gateway for my private net - hence the ethernet card. What do you think,
is a DECstation 5000/125 with 16 MB of RAM powerful enough to route, NAT
and filter a 10 MBit/s network connection?

Basic idea: ''security through unsual systems'' - how many exploits are
there for NetBSD? And how many scriptkiddies do have Mips R3000 Shellcode
for NetBSD sitting around? <grin>

Standard target today seems to be Redhat Linux on x86 (Ramen).


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