SunOS 4.0 and memory

[Perry Hutchison]

In article <2920 at brazos.Rice.edu> drmurray at brocku.ca (Bill Murray) writes:

> X-Sun-Spots-Digest: Volume 8, Issue 192, message 12 of 14

> Are university has 5 sun3/50 (diskless) and 2 sun3/60 (servers) all using
> 4 Megs of memory and running sunOS vers 3.5.

> We would like to upgrade to vers 4.0 of the operating system ...
> I have heard rumors that vers 4.0 needs more than 4 Megs ...

I have heard that 4.0 can be configured (more like stripped) to run in 4
Mb, but it's pretty marginal.  This is still at the level of rumor, but
perhaps a slightly more detailed rumor.

> what is the cheapest and easiest way to upgrade these units?

Memory expansion for the 3/60 should be available from Sun as well as from
other suppliers.

The "official" word from Sun is that the 3/50 cannot be expanded (other
than by adding disk and/or tape to the SCSI port).  However, memory
upgrades of 4 Mb or 8 Mb (for a total of 8 Mb or 12 Mb) are available from
third-party suppliers.  Ads can be found in Unix World and probably other
places.

I have had no experience with any such; however I would anticipate the
following potential problems:

1.  The power requirements and/or heat dissipation of the additional memory
    might exceed the 3/50's power supply and/or cooling (airflow) capabilities.

2.  Since the 3/50 was not designed for memory expansion, these offerings
    have to be connected in unconventional ways.  I have seen a picture in
    someone's ad which leads me to suspect that they plug into the CPU and/or
    MMU sockets on the 3/50 board, and the CPU and/or MMU then plug into
    sockets on the add-on memory board.

These problems must not be insurmountable, or the third-party suppliers
would not be able to stay in business, but there may be a nuisance factor:
if the system is under Sun maintenance you might have to remove the memory
expansion before having it serviced.

If you are using a third-party maintenance organization, you might want to
check with them as to any experience they may have had with this sort of
thing, and whether they would be willing to support it.