its probably bad memory. just fscking or sitting idle, it isnt using much 
memory. give it some work, and it probably hits the bad cell. 
you might try reseating the simms and seeing if better contact on the 
pins helps, or try to find the bad module and tossing it. 

hope this helps,
isildur

On Tue, 1 May 2001, der Mouse wrote:

> I've got a 2100, a pmin.  I dropped some disk on it and installed off
> the 1.4.2 cd, that being what I had handiest.  I'm trying to bring it
> up to the same source tree the rest of my machines run...BUT...
> 
> ...it hangs every time I try to do a make build.  It hangs hard,
> usually in the middle of printing an output line if I'm watching the
> build, or with no output if I'm not.  And it's not just the serial port
> going south, because at the same time it stops answering pings.
> 
> I've been unable to get any response at all out of it when it goes into
> this state, short of the reset button or the power switch, so
> unfortunately I can't tell exactly where it dies.
> 
> My first suspicion was thermal.  I opened the case up and have a small
> fan blowing directly on the CPU; it still dies.  Part of the reason I
> suspected thermal problems is that it will sit there for ages without
> trouble if it's idling at the shell prompt, or if it's fscking disks.
> But start the cpu cranking (= generating heat), and it falls over
> within minutes.  (The last failure, I did a make build and it got as
> far as cleandir in usr.bin/make.)
> 
> And if - as I suspect - I just have toasted hardware :-(, anyone have a
> DECstation looking for a home?
> 
> 					der Mouse
> 
> 			       mouse@rodents.montreal.qc.ca
> 		     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B
>