Summary: DSIMM Instalation Sequence in SS10

From: Jozef Rujak (
Date: Thu Jan 12 1995 - 08:20:16 CST

Sun Managers,

Original query, in short

>Is it possible to change DSIMM Instalation Sequence in SS10 ?
>I have 4 16MB DSIMMs in slots
> J0201, J0304, J0203, J0302.
>Can I use for example slot J0303 instead of J0302 ?
>The instalation sequence in manual is
> J0201, J0304, J0203, J0302, J0303, J0301, J0305.

ANSWER: Yes, it is possible. I did it and it works.

Special thanks to:



------------------------Response Answers--------------------------------

        You should be able to do what you suggest. I believe the usage
of memory will be a bit less efficient, since the OS will have to skip
around inactive memory addresses, but you'll still function.

        The manual should show the address space allocation in the table
which shows slot sequence.

Paul Roland


I found out the other day that some of our SS10s had SIMMs
in the wrong slots; however, the machines had been working



Hello Jozef,

the only "must" is the first slot, i.e. J0201, the sequence is a
recommendation. You just could try if it works with another
permutation. There is no danger for your machine or SIMMS.

CU, Dirk.


Hi Jozef,

I am not sure which memory baords use, I mean the vendor.
I have found that the manual that comes is not very helpful.
It tills you where the mem boards need to go, but does not
tell you why it can't go any other way. Initially, I followed
the instructions religiously, Last time just for a change,
I tried installing, i.e filling all the slots in sequence
from the first slot ie you facing the system. It is
working fine so far, didn't get any erro message so far.




        You can move simms around with the slots, the spec'd order of
simm placement was for performance reason's, ie memory access patterns
and memory recovery times, bus length etc. There was a bug that required
the LARGEST simm to be the first simm or the Sun had trouble, but other
than that, changing things will still work, although slower somewhat.



The order that SIMM is in is not as important as having all neccessary
simms slots filled.
A certain number of simms make up a SIMM memory back, I beleiev
there are 4 such banks in a SS10.
You have to fill all simm slots in memory 0, which may be
the J0#'s that you sent me, there are usually 8 or 4 slots to a
bank, make sure you have them all filled. Also try taking out more memory
and seeing if the machine responds better than you can start adding
them in the quantity that is expected.

Good Luck,

Robert Tag


I had an FE tell me that the only slot that required a simm was the first
slot (probably J0201, I don't have one sitting in front of me to tell), and
the others could be in any sequence. One way to try is to move the simm,
boot the workstation and see if you still get 64 mb at boot up.

This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:10:14 CDT