🚀 go-pugleaf

In article <1990Apr12.024039.851@csis.dit.csiro.au> scott@csis.dit.csiro.au (Scott Milton) writes:
>Dear Net.users,
>
>Problem: DECStation 3100 does not recognise extra 16MB of third party memory.
>
>Details: Memory is "Dataram", purchased from a local supplier "Kairinsky".
>         The DECStation originally had 8MB of memory, and now has 24MB.
>	 Useful diagnostics are:
>		>>> test -c
>			MEM 24Mbytes
>		>>> auto
>			loading rz(0,0,0)vmunix
>			Ultrix Workstation V2.1 (Rev. 14) System #4 ...
>			real mem  8388608
>			avail mem 5558272
>	I've tried a few bizarre things, such as reconfiguring the kernel,
>	using the kernel from a 16MB machine, booting off another disk which
>	serves a 16MB machine, and the result is the same.
>
>	I've also run a thrashing program (random accessing a configurably large
>	memory array) to test how much memory is being used, and verified that
>	the machine is actually only using 8MB.
>
>	Some of the old Suns needed to have their eeprom values changed when
>	more memory was added, but this in not in the manuals, and nobody
>	I've talked to locally thinks this is likely.
>
>	Any suggestions, however slight would be appreciated,

I have a DECstation 3100 that has 3rd party memory with no problems. The
peculiar part of your problem is the CPU ROM recognizes all the memory,
but ULTRIX does not. >>>test -c and the powerup memory test are not very
thorough in testing memory. Their is a better memory test that is not as
well known:

	>>>t m

This does a much more thorough memory test by writing different patterns
and checking parity. If this test encounters a problem it will tell you
whcih SIMM(S) is in error. The CPU might recognize all the memory, but has 
mapped out bad SIMMS and only tells ULTRIX about good memory. I am not sure 
of this but it is a possibility. If the memory immediately following your
DEC memory is bad it might just mark all memory after that is unusable.

Their is also another diagnostic that runs from ROM that will tell you if
their are any bad pages on SIMMS. 

	>>>t b

This will come back and list all SIMM pairs and indicate if any pages are
marked 'bad'.
>
>Thanks for your time,
>-- 
>Scott.Milton@csis.dit.csiro.au     Phone +61-6-2750923     Fax +61-6-2571052
>CSIRO Division of Information Technology, ANU, Acton Canberra ACT AUSTRALIA.


Good Luck!


Chris Martel
Clearpoint Research Corp.