On Wed, 12 Sep 2001 00:29:59 -0500, Mark Rode wrote:

>Subject: Compaq Pressario 2240
>
>I am working on a Compaq Pressario 2240. The online manual and Compaq tech
>support has advised me that this computer has 16 megs or ram soldered on
>the motherboard and a 16 meg SDRAM in the DIMM slot. Visual inspection has
>confirmed this. I have been told I can pull the 16 in the DIMM slot and put
>in a 32 for a maxim of 48.
>
>  Is 48 the absolute top...is this a BIOS limitation. 

Highly unlikely its merely BIOS! It is VERY likely a motherboard
design issue.

Early SDRAM like back when 32MB was the biggest cheese was so
"bleeding edge" that  it had standards all over the place. In fact the
transition from EDO was rocky. Though SDRAM was when installed in
66MHz Pentium boards no faster at all than EDO 60 it was deemed a BIG
selling feature.

They finally worked out how to make it.  But whoops! Then had  to put
on a programmed SPD a teeny tiny EEPROM chip to be compatible with
intel's  PII LX chipset!

After that organization of SDRAM memory chips changed several times
and various different ways of organizing the affordable chips on DIMMs
were worked out.

Saying its an SDRAM DIMM is sort of like saying "its a car engine
using internal combustion technology". They vary considerably.
And  details are both hard to come by and harder to interpret.

Now RAM is often sold as a generic commodity but mostly its hard to
find anyone who can predict  even whether this or that SDRAM on sale
will work in an "ancient"  BX chipset based board much less LX or TX
board.

As for boards using two banks of  16MB or 32MB SDRAM DIMMs  they are
even more finicky.

I just finished upgrading RAM in an IBM  P166 which came with one 16MB
DIMM of SDRAM. Has two DIMM slots. No soldered RAM. 

Its been happy with 16MB and Windows 98 for light websurfing, plenty
email and lots of word processing, web greeting cards. AOL, Juno  and
etc.  I also had no trouble using it with my standard ISP or using IE
to right click on links and have several windows open plus multiple
downloads.

The documentation said it could take up to two 32MB unbuffered SDRAM
168PIN DIMMs.I tried lots of different 32MB pieces I had. Old and new
amd 64s one at a time. None worked.  

So I asked Crucial and though it was NOT on their  memory selector
they had records of success with a certain part number. So I ordered 2
32MB pieces for $35 each. They work perfectly. 

 I ran the full Memtest86 a very thorough memory test freeware at 

http://www.teresaudio.com/memtest86/

Anyway now the grandparents have a FAST computer! And it is still the
very one they are familiar with!

>Has anybody tried
>putting a 64 for a total of 80 in here ? 

I have tries in other model computers with similar soldered on RAM.

>Is the SDRAM proprietary

There is really no such thing as proprietary RAM (except for some
laptops). Just evolving technology, and changing manufacturing
methods. Different circuitry on tiny the DIMM and SIMM boards and
re-engineering of RAM chips.

 The absolute priority being to reduce production costs a tiny bit and
increase yield and if possible eaking out small (but exaggerated)
performance gains if only for a sales point. Motherboard manufacturers
design to accommodate what's soon and recently available. Since more
than 95% of RAM is used in new builds with current boards
(contemporary with the RAM) that's mostly what they care about.

Typically RAM mfgrs will test new module designs in a few recent
boards. Maybe Intel and Asus for instance. Motherboard makers will
test several brands in their boards and maybe not even share the info.
Tier 1 VARs like Dell and Compaq KNOW what they used themselves.
Its in no way proprietary except that they bothered to test it. They
have zero motivation to know anything about other parts they don't use
or sell. Their price for their warehoused stock of older "repair
parts" depends on how they inventory such  things.  Some keep them at
original price, some depreciate them and some add annually for
warehousing costs.

Many changes in PCs are motivated by new production methods first for
the sake of  better technology eventually. The switch to SDRAm to AGP
video cards. Socket 790 vs Slot one. Even 133MHz vs 100Mhz parts. They
ring a bell as being a "good buy" because they cost a little less and
are theoretically potentially better but are often not compatable with
anything but the latest other stuff. 

(Thus onesees the new low price on a fast CPU and think of upgrading
that but when you find your System needs  the Slot one Pentium  or
can't take the 266FSB  Athlon AND the older part not only is "worse"
but $30 more ,, wekk that often sells a whole new system. For many
users its months before they can do what they once did as they must
first  relearn all new everything.  

>Compaq  ... or will any SDRAM work ?

I am sure from similar experiences that MOST will NOT. 

 Compaq Pressario 2240 IS listed in the www.crucial.com memory
selector. The 32MB part is about $36.  The resulting 48MB is good
enough for many people. It was good enough for us not that long ago
and RAM cost lots more!

Mark Paulson

San Jose, California

Silicon Valley

- Warning: Pontif has stepped off the soap box. :)

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