SIMMs for Sun 4/110 (a summary)

[Pasi Koikkalainen]

SIMMS FOR SUN4/110 (Summay at last...)
_______________________________________

This is a summary of answers for my inquery that was posted a log time
ago. I sorry that it took so long to reply (we spent some time to find out
what was the real problem and I have been travelling a lot lately).

My original question was:
>Have anyone upgraded memory for Sun4/110 ? 
>Our factory configuration was 8Mb with 256 Kb SIMMS
>and we wanted to upgrade it to 20 Mb using 1Mb SIMMS.
>We used same type of 1 Mb SIMM:s that we have been using
>for Sun 3/60 but it seems that the ones for sun4/110
>are something else. 

I got many (wrong) answers, thank you anyway....

Most answers suggested that the difference between sun 3/60 and 4/110
SIMMs is 100ns vs. 80ns timing. In fact sun 4/100 works well with 100ns
RAMs also and you can mix 100ns and 80ns SIMMs. (We have now 4MB 80ns and
16 MB 100ns SIMMs). The real difference was pointed out by Ken Schmitt
(Acropolis Systems, Inc):

>Some of the SIMMs that Sun shipped with the 3/60s can be used for
>the Sun-4/110; others cannot be used.  Sun-4/110 requires 80 nsec.
>Static Column DRAM (SCRAM) SIMMs.  However, it also works with
>80 nsec. Page Mode DRAMs as well (most of Sun-3/60s were shipped 
>out with 100 nsec. Page Mode DRAMs though).  Sun-4/110 do not work 
>with "regular" (old type) and nibble-mode DRAMs.

80ns is not the requirement but "Static Column DRAM (SCRAM)" is.  We have
now Toshiba TC511002P/J-10 (Static Column  100ns 1MB DRAM) and it works
ok. Compatible RAMs are for example TMX4C1027 (TI), HM511002 (HITACHI),
uPD421002C/LA (NEC). 

I will not include a price list of different suppliers since the ones I
have are good only in Finland (I know there are BIG differences,
especially in USA and in Japan).

Pasi Koikkalainen
Lappeenranta Univ. of Tech.
Information Tech. Laboratory
P.O.Box 20, 53851 LPR
Finland
e-mail: koikkalainen at ltkka.lut.fi (more secure) or
        pako at neuronstar.it.lut.fi

By the way, some old documentation about memory jumpers in sun 4/110 was
wrong too.