By: Dan Casey (dcasey@ameritech.net)
http://www.ameritech.net/users/dcasey/index.html
Welcome to the first installment of, what I hope will be, a continuing series
of articles and discussions on OS/2 Technology issues. With more and more hardware
vendors taking the easy path to developing and manufacturing products to Microsoft's
specifications, Compatibility in the OS/2 environment is becoming a bigger issue.
The facts presented, here, are based on my own research and personal experience,
and thus, cannot possibly cover all of the different choices available (I do have
a "Real Life" and a real job). So, after reading this article, if you
have any additions, corrections or comments, you can e-mail me at voicevp@ibm.net
and the next article will incorporate readers comments, suggestions, additions and
corrections to this article.
The answer is: There is no simple answer. Every user's needs are different.
So, how do you choose?
By being informed. By knowing the options available to you, and what these options
are capable of.
Without getting into too much technical detail, I'll outline the basics.
Many users don't realize that all chipsets do not cache memory above 64meg. ( I
didn't). But, if you intend to install more than 64 meg of RAM on the system board,
you need to know which chipset is capable of caching all that ram. OS/2 addresses
RAM all at once. It doesn't know from base, upper and extended RAM. So, you'll want
to make sure that the system board and chipset in you system is capable of caching
all the RAM you have installed.
This article is limited to Socket 7 Chipsets (Pentium class). Pentium II chipsets
are not included, as the max cacheable RAM areas are higher than 64 meg.
TX and VX chipsets are not capable of caching more than 64 meg of RAM.
The Busmastering (UDMA) IDE drivers in OS/2 support these chipsets.
I don't recommend these chipsets simply because of the max cacheable ram area limits.
However, they do work with the Busmastering (UDMA) drivers from IBM (IBM1S506.ADD).
The HX chipset is capable of caching up to 512 meg of RAM, provided the Cache Module
is at least 512k, and contains 2 TAG RAM chips.
The Busmastering (UDMA) IDE drivers in OS/2 (IBM1S506.ADD) support this chipset.
This chipset is no longer manufactured by Intel. But Motherboards do exist with
this chipset.