Adrian C <email@here.invalid> wrote in
news:7aagbtF1un4qhU1@mid.individual.net:

> Barry Watzman wrote:
>>
>> One other question, what does EISA stand for? Back in the 1980's it
>> stood for "Extended Industry Standard Architecture", an architecture
>> of a new system bus designed by Compaq and Zenith and a few others to
>> compete with the "Micro-channel" architecture from IBM. It never was
>> commercially successful and it died more than 20 years ago. So why
>> is this partition called an EISA partition?
>
> Because it's tagged with the same partition table identifier 12h (18
> decimal) that was used when the disk space were originally used to
> hold the then necessary configuration program for those early
> jumperless EISA systems, accessible using a defined key sequence
> during boot. The tag name stuck for a lot longer than the technology
> of EISA and MCA.
>

Barry,

The gist of Adrian's answer is don't get sidetracked by focusing on
"EISA"--it's probably just a masquerade to throw you off the scent.
It's not uncommon for computer makers to "hide" their own custom
utility, diagnostic, or recovery partition by simply changing the
"partition-type" code in the partition table, which causes operating
systems like Windows to think it's something foreign when it's really
not.

For instance, Dell's utility partition is a plain old FAT16 partition,
but Dell changes it to the EISA type-code in the partition table to keep
Windows from tampering with it. It's not an EISA partition, but Windows
thinks it is because that's what the partition table says. But when you
select the option to boot the utility partition, the bios changes the
partition table descriptor on the fly back to FAT16, and voila! An
ordinary FAT16 partition boots to a DOS environment.

There are tools around that will look into the partition's boot sector
to reveal what the partition type truly is, despite what the partition
table might have you believe. I use Mikkelsen's Findpart
(www.partitionsupport.com) for this purpose, but I'm sure there are
others as well.

If Findpart says it's really FAT32 or NTFS, I'd try temporarily
"correcting" the partition table descriptor manually, making it active,
rebooting, and seeing what it boots to. (Ptedit and ptedit32 is the
easiest way to fiddle with the partition table.) Given the size, my
guess is it may be a FAT32 or NTFS partition that boots to a WinPE-based
repair or recovery environment (although the actual recovery image or
content may reside on CD or DVD).

That might give you a clue as to what it is, but not how you're normally
expected to get to it. Manufacturers have used various methods of
unmasking the partition when they want to use it, such as a customized
bios option, or magic keystrokes at POST or boot time, or a customized
diagnostic/recovery CD that you boot from and when it boots it runs a
utility that unmasks the partition.