Adding RAM to 6386 16mhz...help with settings

[Bob DeBula]

To answer your questions as best I can (I have a 6386 and did upgrade
the memory some time ago).  You want SIMMs. You want 120ns or faster
(100ns or 80ns) SIMMs. You want low profile SIMMs or you can kiss the use
of one of the 6386s too few expansion card slots goodbye.  You *must*
have either all 256K or all 1Mb SIMMs on a memory board (mixing them is
a *big* NONO).  If you decide to go to 4Mb and no further, then you can 
get 256K SIMMs and load the board full.  If you wish to someday go beyond
4Mb, then you need to look at selling your 256K SIMMs and replacing them
with 1Mb SIMMs.  You must upgrade in 4 SIMM increments (due to the 32 bit
memory access).  The SIMMs must have the parity chip (i.e. they must be
256Kx9 or 1Mbx9).  Figuring out the DIP switch settings is the stuff of
which data processing legends are made. It is not simple & has no easily
grasped underlying logic that an ordinary mortal would understand as far as
I know.  AT&T includes a smallish pamphlet with *their* memory upgrade
explaining how to set the DIPs. I won't go into my opinion of vendors
who don't include 25 cent pamplets with $3,000+ machines at this time (I've
flamed 'em before on here for this one).  When I posted the same request
there were many folks (resellers mainly) who offered to send me one
of the many of these they had from installing AT&T upgrades for systems
configured with AT&T upgrades.  Todays project (for which someone would gain
AT&T 6386 users undying gratitude) would be for someone to write a program
which eliminates the need for the book (i.e. you tell it what you want
to upgrade to & it tells you which  SIMM sockets and which DIP switches).
For someone who understands the rational of the methodolgy used for the settingsthis should be a piece of cake (not me: I haven't spent enough time looking
at it to understand it and I doubt it would be a requirement in VCR
instruction sheets (although you never know, VCR vendors also masters
of confusion and are always
on the lookout for archane ways to confuse the poor purchaser who just
wants to tape Dr. WHO on Saturday nights) :-).           
-=-
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Bob DeBula                    | Internet:   bobd at hpuxa.ircc.ohio-state.edu
The Ohio State University     | Disclaimer: These are my views, not the U's