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Date: Fri, 22 Mar 1996 10:56:56 -0700 (MST)
From: Stephen Mathezer <mathezer@newera.ab.ca>
To: questions@freebsd.org
Subject: Help.  Adding memory broke my machine
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I have a no name 486-66 VLB motherboard.  It has 4 30 pin and 2 72 pin 
slots for memory.  Up to this point I've been happily running 2.1 release 
with 16M of memory (4 30 pin simms).  I recently got an additional 8M 72 pin
simm.  The instructions for the board say that I can not have all 6 
memory slots filled but that 4 30 pin and 1 72 pin simm a supported 
configuration.  Indeed, Windows 95 works fine with the added memory, 
however FreeBSD does not.

It actually performs much slower than with 16 M than with 24M or memory.  
Plus as soon as I try to do anything in X and I presume anything more 
intensive in general I get sig 10s and sig 11s all over the place.

I turned off all shadow in the BIOS to no avail.  There are also two 
other configurable options in the BIOS:  External Cache (secondary cache 
memory) and Internal Cache (CPU internal cache).  If I turn both of these 
off then things work but they of course work slower than they did with 
16M of memory with caching on.

For what its worth, I have BOUNCE_BUFFERS enabled in the kernel.

I don't know that I can tell you very much about the board.  The only 
reference to an actual name in the manual is as "The 80486 Deep Green 
mainboard"  

Can anybody give me any ideas for what I can do to make this thing work 
with the extra memory?  If you need more information tell me what to do 
to provide it.

Oh yeah, I did try removing all the 30 pin memory and using 2 72 pin 
simms and that configuration was OK.  I guess I should have tried it with 
just 1 72 pin simm but I didn't think of it at the time.

Thanks for any help

-Steve