Hello, Roy.  Writing in haste, here.  Behind on everything.

 JH>   A lot of the newer, larger 72-pinners
 JH> use 4K refresh, and some older boards only support 2K refresh.
 JH> When that happens, SIMM isn't recognized as full-size.

 RJT> I've never heard of this before,  but I think I know what you're
 RJT> talking about.

I'm no expert on it either, but AFAICT it has to do with the bandwidth
at which the SIMM memory is refreshed -  sumpin about 2K lines at a time
vs 4K lines at a time.  (whatever a line is, I dunno).

 RJT> Oh?  I haven't looked at it in detail yet.  I suppose it'll make a good
 RJT> home for one of those chips I took along,  which as I recall were
 RJT> slower parts (though I can't make much sense out of the numbers on
 RJT> them,  gotta look it up in the book).

For P1, easy to decipher, but look in the book about voltages and etc.,
based on the "SY" number on bottom of chip.

 RJT> Speaking of parts I took along,  that cache stick is an interesting
 RJT> critter. There's a jumper on there that's even labeled,  says
"Pentium"
 RJT> and "Cyrix". There's also a warning sticker on the back
that says "For
 RJT> G586PM series only" and "You must take full responsibility for any
 RJT> damages that may occur if otherwise used".  Interesting stuff...

I've seen that type of warning before.  Pfscarey.  Maybe G586PM is a
Gigabyte part - - I dunno. You might try a Google search when you next
stop by the library.

 RJT> There's also a "256" written in to a portion of the part
number on the
 RJT> front side.  Looks like it'll drop right in to the cache socket that's
 RJT> on the board on my desk,  which is not quite as tall a part labeled
 RJT> "Corsair Microsystems CM2258FX-6" but not otherwise identified.

FWIW, I have a Corsair COAST module here also, but clearly not the same
as yours.

 RJT> book doesn't go into this stuff much,  talks about "referring to the
 RJT> documentation that came with your MB" and "getting the
databooks"
 RJT> (hah!) and similar stuff.

AFAIK, even with the manual, from mfgrs up to Asus level,  the info
about these COAST modules is very scant. Voodoo, no longer available,
and etc.

 JH> So, should I forget about sending you VX board(s)?

 RJT> Not.  I'm just a little disappointed that there's that limit there in
 RJT> terms of where I can go with them.  I can think of maybe a couple of
 RJT> instances of stuff where I'd like to go much further than that with
 RJT> ram,  and maybe even go with ECC or at least parity ram, 

You're disappointed that 5-7 year old VX mainboards which now come to
you as freebies limit you as to where you want to go now at the end of
2002? C'mon, Roy.  If they still had value even up to around $15 a board
they wouldn't be freebies, even from a generous feller such as myself,
would they?

 JH> Intel's only chipset of that vintage which supports parity SIMMS is
 JH> the 430HX. That one _can_ cache up to 512MB of parity SIMMS, but my
 JH> book cautions - - "Most 430HX boards shipped with a tag chip that
 JH> could only manage 64MB of cached main memory, while you could
 JH> optionally upgrade it to a larger capacity tag chip that would
 JH> allow for caching the full 512MB of RAM.'

 RJT> Key words there being "of that vintage".  :-)

Hee.  I think they may have stopped production of HX chipset boards back
around 1997.  Recent in yours and my years,  older in doggie years, even
older in 'puter stuff' years.  Now 'Vintage.'

 RJT> I wonder what that tag
 RJT> chip is that they're referring to?  From the earlier stuff (386, etc.)
 RJT> I seem to remember cache being a bunch of DIP-socketed stuff,  and in
 RJT> fact some of the boards I have on hand have those sockets *empty*.
 RJT> They were different sizes of chip,  and I believe one of those was
 RJT> designated as a "tag" ram.

Looking at 2 different boards with slots for COAST modules - - One, with
256KB onboard already,  no slot available for added Tag Ram.  I guess it
already has enough onboard to cover an added 256K COAST module. Second,
and Asus P55t2P4 board, with 256K already onboard - -has a slot there
for an added tagram chip to cache more than 64MB - - add that and an
appropriate COAST module of 256K and off you go,  if you can find them.

 RJT> The cache stick that was with those Pentium chips has just two big
 RJT> chips on it,
 RJT>  UMC parts labeled 3232,  and two sets of pads on the other side
 RJT> labeled 32K*32 which probably accounts for the cache ram itself.

Sounds right, but no small tagram chip on the COAST stick?  Even if
there, from what I've read, that may not cover the mainboard/chipset
requirements for caching more than 64MB.

 RJT> one that's *in* the MB has two similar chips on it.  One has that paper
 RJT> sticker I mention above and the other is marked Galvantech
 RJT> gy17132C32Q-6 (both similar chips) _and_ a smaller one marked N321256J.
 RJT>  I'm thinking that in this case _that_ one is likely to be the tag ram
 RJT> and that the other cache stick wouldn't likely work in this board.

Sorry, I got no time to try and look up those chip numbers.

Good luck - - -  JimH.

... "Bother!" said Pooh, as he realized his entire 'puter system
is obsolete.

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