Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!wuarchive!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!dsinc!netnews.upenn.edu!vax1.cc.lehigh.edu!cert.sei.cmu.edu!krvw
From: walker@aedc-vax.af.mil (William Walker C60223 x4570)
Newsgroups: comp.virus
Subject: Re: Software Upgradable BIOS
Message-ID: <0003.9105301427.AA10625@ubu.cert.sei.cmu.edu>
Date: 29 May 91 13:15:00 GMT
Sender: Virus Discussion List <VIRUS-L@LEHIIBM1>
Lines: 61
Approved: krvw@sei.cmu.edu

Vergil William de Comyn ( decomyn@phoenix.css.tek.com ) writes:

> Intel is planning on using Flash EEPROM technology, but, as I
> understand it, with a twist -- The user will have to explicitly
> activate the reprogramming function by pressing a button, flipping a
> switch, or some similar physical function.

It's good to know that they are tying the BIOS upgrade to hardware in
some way.  One interesting feature of this would be that knowledgeable
users could make BIOS patches rather simply; and it would make bug
fixes easier.  One drawback would be that pirating of the upgrades
would be easier, which may end up making the upgrades more expensive.
I still think there's too much inherent risk in it (my opinion), and
would prefer a ROM BIOS (also my opinion).

Also, I find fault in the logic behind one of the reasons for making
an upgradable BIOS: "to get the full benefit of a CPU upgrade" (no, I
don't find fault with the benefit itself -- read on).  This is in
reference to the newer machines which have a replacable CPU on a
little card.  Glenn Henry, Dell's VP for marketing, says, "You can run
your old 386 BIOS with a 486 upgrade card, but you'll pay a
performance penalty unless you install a fully coded 486 BIOS." If
you're gonna have the case open to replace the CPU, how much trouble
would it be to replace the ROMs while you're at it?  For that matter,
why not design the replacable-CPU system so that the BIOS is on the
replacable card, to automatically upgrade the BIOS too?  Cost
shouldn't be a factor, since compared to the cost of the machine and
the CPU upgrade itself, a ROM BIOS upgrade would be inexpensive.

One last thing before I shut up.  I wrote:

> >                            The term I saw was "erasable programmable
> > read-only memory (EPROM)," but more likely the actual technology
> > in the chip is EEPROM (electrically erasable programmable ROM) or
> > EAROM (electrically alterable ROM).

and Jeroen. W. Pluimers <PLUIMERS@rulcri.leidenuniv.nl> wrote:

> From what I understand this is quite common, most ROM BIOS
> manufacturers use EEPROMS which can be repogrammed when you have:
> a) the new EEPROM image (on disk or as an (EEP)ROM)
> b) and EEPROM programming device that can program that kind of EEPROM
> c) a very strong UV lamp to erase a programmed EEPROM

EPROMs are erased by UV light and are programmed from disk or ROM with
a programming device.  EEPROMs ( ELECTRICALLY erasable programmable
ROMs ) are not UV-erasable, and a programming device is not used to
program them (normally).  They are erased by a signal on one of the
leads, and are reprogrammed in place in the circuit.  EAROMs operate
similarly.  That's the whole idea behind Intel's plan -- to reprogram
them in place in the PC from software, to save having to remove and
replace them.

Anyway, I've said probably more than my share on this, so I'll hush
("...and there was much rejoicing."  -- Monty Python)

Bill Walker ( WALKER@AEDC-VAX.AF.MIL ) |
OAO Corporation                        |
Arnold Engineering Development Center  |  AEDC -- Home of the "Chicken Gun"
M.S. 120                               |
Arnold Air Force Base, TN  37389-9998  |