access to BIOS of DECpc

From: Roger Merchberger <>
Date: Sat Oct 23 10:18:16 2004

Rumor has it that Vintage Computer Festival may have mentioned these words:
>On Sat, 23 Oct 2004, Gooijen H wrote:
> > A short update on my efforts ...
> > The Fujitsu-OnRack version did what was to be expected: it checks and
> > sees that there is no Fujitsu drive in the PC and stops :-)
> > Sorry to say that the version from Pete is for Western Digital drives
> > and shows the same behaviour :-(
> > I found a gfew manufacturer versions, but not for HP &%$#_at_!&
> > However, there is till hope at 2 fronts: the version Dave will dig up,
> > and there is one on auction at eBay (for just a few $$). If I will be
> > the lucky winner I will share the data on the disk with everybody that
> > is interested in a copy. It looks like this is an *original* OnTrack
> > version that works with drives of any manufacturer. It's version 7 ...
> > I'll report back later.
>Maybe this is a dumb suggestion, in which case I invite folks to throw
>pies at me while I'm stripped down nekkid (note: I might like it),

If you're talking Lemon Meringue fresh outta the oven, I doubt you'd like
it (well, not for *long*, anyway! :-O )...

>... but
>what about using a boot manager instead? Would it not accomplish the same

Noper, two totally different critters.

Boot managers just *replaces* the standard MBR with a customizable MBR so
you can boot multiple OSs. It has nothing to do WRT disk geometry or sizes.
Linux's Grub is a good example. (LILO can do it too, but it's a little less
forgiving of other operating systems.) Even Winders NT/2K/XP boot manager
can be twiddled enough to boot Linux, tho it's *not* easy to do. Individual
partitions are easily accessible from other OSs as the geometry is still
derived from the BIOS/HD itself.

OTOH, OnTrack (and others) actually "off-shift" the MBR and add a
"pre-loader" which adds a BIOS patch to give the BIOS the ability to
recognize larger HDs, or HDs with odd geometries. Then once it loads, the
off-shifted MBR is then called and the computer can boot normally. If this
BIOS patch is *not* loaded first, then the computer cannot accurately
recognize the HD geometry, partition sizes or locations, etc.

On the plus side, it's *very* handy every time an idiot PeeCee manufacturer
decides to hard-code YADAHDL (that's "Yet Another DumbAss Hard Drive
Limitation... ;-) -- First 32Meg, then 528 Meg, then 2Gig, then 8 Gig, then
80Gig, then 127Gig, and I'm sure there's others in between I've forgotten.
This code allows a computer with a 528-Meg BIOS limitation (or older
computer who's BIOS doesn't have customizable entries) to utilize larger HDs.

On the minus side - He who uses this software had better take care on
having a good backup plan in place that does not require this software! As
the geometry's been "jumbled" to make it work in that environment, if you
yank the drive & put it in another machine, the partitions won't be
recognized or anything. With OnTrack and some others, you *could* set up a
boot floppy with the special code so another machine (if booted from this
floppy) could read the partitions & whatnot, but guaranteed, as soon as you
need that floppy, you won't be able to find it... ;-)

Hope this helps,
Roger "Merch" Merchberger

So what kinda pie do you want, Sellam? ;^>

Roger "Merch" Merchberger   | A new truth in advertising slogan
sysadmin, Iceberg Computers | for MicroSoft: "We're not the oxy...          |                oxymoron!"
Received on Sat Oct 23 2004 - 10:18:16 BST

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