[SunRescue] VME expansion card?

[James Lockwood]

On Wed, 28 Jul 1999 apotter at icsa.net wrote:

> > Does anybody know where I can get a VME Ram expansion card for my SS 4/330?
> > It has 32 ram in it right now, and I can get 32-pin true parity simms pretty
> > cheap ($13 for 4meg) so I'd like to bump it to as high as it can go.
> 
> The memory expansion cards for the 330 are peculiar to the x30 chassis, and 
> (used to be) expensive.

They shouldn't be anymore.  Two years ago I was giving the 3U boards away
for $10 and having trouble moving them for that price.  The 9U boards (48
SIMM slots) seemed to go for more (though I got one fully loaded with 48
1MB SIMMs for $50 at the time).  If the original poster is really
desperate I can probably scrounge another 3U card up from a friend (who
was up to 5 4/330's last I checked).

One thing to be wary of, however.  If this system has 32MB in it now, then
I assume that the 8 slots on the motherboard are filled with 4MB SIMMs and
there are no expansion cards present.  This was never a "supported"
configuration for the 4/330 as the 3U memory cards may overlap that
address space.  Once upon a time I had great difficulty making this setup
work, but that was with an old boot PROM revision (3.0.1 I believe).  My
advice to you is to fill the mainboard with 1MB SIMMs and use 4MB in the
expansion cards if you experience problems with recognizing memory on
powerup.  J0902 must be removed if 4MB SIMMs are installed on the 3U
cards, and J0901 must be installed if the card is only half-filled (8
SIMMs instead of 16).

Contrary to what nearly everyone will tell you, you _can_ put the 9U
memory expansion board (with 48 SIMM slots) into a 4/330, but it's a
little bit tricky.  You have to jumper BGxx and IACK for slot 1, pull BGxx
and IACK for slot 2, put the CPU board in slot 2, and put the memory
expansion board in slot 3.  This means that you can't have a P4
framebuffer in the system as there is no space next to the CPU board. 
This works because the primary P2 bus goes between slot 1 (where the CPU
board normally plugs in) and 3U slots 4 and 5 (where the memory cards
normally go).  However, there's a secondary P2 bus that only goes between
slots 2 and 3.  For real fun, you can actually fit 2 4/300 CPU boards into
one 4/330 chassis and use the 3U slots for memory for CPU board #1 and the
9U slot for board #2, and you end up with 40 and 56 SIMM slots total for
two CPU's in the same chassis.  You do have to pull all of J3001 on both
boards as well as J2800, J2801 and J2803 on the secondary CPU board IIRC. 

What can I say, in 1990 it was impressive.  :-)

-James