> First of all, thanks to everybody for their suggestions. A few moments
 > ago we replaced the RAM modules with new ones, we tweaked around with
 > the BIOS settings, we changed kernel settings and all that we could
 > come up with. It didn't help, unfortunately.
 > 
 > Every time we boot the kernel with the EXTMEM setting set, we get the
 > following error:
 > 
 >  | panic: ptdi: 1b9023
 > 
 > The same kernel without EXTMEM set boots fine, but the machine is
 > working very unreliable, because processes receive a signal 11 at
 > random times, or they simply core dump without further explanation.
 > 
 > Any ideas anyone?
 > 
 > 	-peter

Hmm. Is it true that if you put the original, old, 64 MB of RAM back in (and
none of the new stuff) then the old kernel works?  How about the new kernel?

If it is true that the original RAM works with both kernels, then you
should try removing the original ram and putting in only 64 MB of the new
RAM. Of course, this won't work if you have those big 64 MB modules, unless
they are DIMMs, then it will. You can't debug hardware and software together,
so you must first locate the problem area.

What's the brand and model of your system board?  Do you know what SIMM
organizations it supports?  And what organization you are installing?
And even if the chip set supports both fast page and EDO, say, it might
_not_ support a mixture of both, I don't know if they do that or not.
It's always the same for a given chipset, of course, so the chipset
should be identified.
----------------------
Ross Harvey	Avalon Computer Systems, Inc.		  ross@teraflop.com
		Santa Barbara	 		    http://www.teraflop.com