coppi@groucho.caltech.edu (Paul Coppi) (07/24/89)
Hi,
Does anybody know how to go about expanding the memory on a
DECstation 3100? We are considering purchasing DS3100s to run
some memory-hog applications. Unfortunately, we cannot currently
afford DEC's price for memory upgrades. Do any (cheaper) third
party vendors exist? On our Sun 3/60, upgrading memory consists
simply of plugging in 1Mbitx9 SIMMS which cost < $200 each.
Can something similar be done with a DS3100? (Unfortunately we
don't have a DS3100 to open up and look at.) If the DS3100 does
use SIMMS, does anyone know their specifications ( 1Mbitx9, 1Mbitx8?
access time, manufacturer, part number, etc.)?
Thanks for your help. We will post a summary of any replies
received.
Paul Coppi (coppi@groucho.caltech.edu, coppi@caltech.bitnet)
Caltech, Theoretical Astrophysicsjg@max.crl.dec.com (Jim Gettys) (07/25/89)
I've seen at least three annoucements in the last month for 3rd party memory for the DECstation 3100. Go dig up your favorite trade rag... At least one was significantly cheaper than our current price. Then go to your DEC salesman and beat him up on general principles (we lose enough salesmen, we lower memory prices; its a bit hard on the salesmen, however). The SIMMS in the DECstation are not compatible with any others on other machines; "standard" SIMMS would not have been fast enough for the machine, it turned out. Each SIMM holds 2 megabytes, but they must be used in pairs, due to the organization (ergo the 4 meg. size of upgrades). - Jim
lgl@blake.acs.washington.edu (Laurence G Lundblade) (07/28/89)
We got some memory upgrades from Dataram (Princeton NJ) and they had
the best price of about $1300 for 4Mb. They are also specifically for
PMAX's so standard 1Mbx9 etc won't work.
They are easy to install if you know the trick of sort of twisting
them in. That is you don't insert them straight into the socket like
you might imagine rather you lay it in socket and rotate it to the
upright position. This took us a while to figure out so I'll hopefully
save some one some trouble.
rotate <- //
// Simm ||
// ||
#/ #||
# # #|#
### socket ###
============================================
Laurence Lundblade 206-543-5617
lgl@cac.washington.edu.
Networks and Distributed Computing, U of Washington, Seattle WAjg@max.crl.dec.com (Jim Gettys) (08/02/89)
Be careful installing memory SIMMS; people have been known to break the connectors on the motherboard, resulting in a repair you get to pay for. In particular, be careful removing the drive plate with disk drives installed; if you drop it, it can land on the memory SIMMS and you can damage the connectors on the motherboard. It is remarkably heavy and awkward when one or two RZ23's are installed on it. This is why we have field service install the memory SIMMS when you get memory from DEC; we judged the probability of damage to the machine by people not mechanically inclined to be too high. Hopefully we'll get things better on the next machine to the point that these worries will not occur. - Jim Gettys