DEFMTH5.CVP   920105
 
                      More hardware myths
 
I am indebted to Padgett Peterson for reminding me of some
additional "hardware" viri which have occasionally been
reported.
 
1) "Lethal Floppy Eject" aka "Toaster" virus
I think this one belongs with the users who can't find "Any"
keys, photocopy floppies and can't see whether the screen is on
because the power is off.
 
2) "CMOS" virus
3) "BIOS" virus
4) "Battery" virus
These three are all variations on a similar theme.  These types
of viri are reported regularly.
 
First of all, BIOS is ROM BIOS.  The RO in ROM stands for "read
only".  The BIOS, therefore, cannot be infected by a virus.  At
least, not yet.  Intel has already developed flash EEPROMs which
it is pushing as "upgradeable" ROMs for the BIOS.  It *is*
possible to get "bad" ROMs, and it is even possible that a run
of BIOS ROMs would be programmed such that they constantly
"release" a virus.  It hasn't yet happened, though, and it is
extremely unlikely, as well as being easy to trace.
 
The CMOS is stored in RAM, and can be changed.  However, the
CMOS table is stored in a very small piece of memory.  It is
highly unlikely that a virus could fit into the "leftover"
space, even though the theoretical limit of the "minimal" family
is about 31 bytes.  More importantly, in normal operation the
contents of the CMOS are never "run", but are referred to as
data by the operating system.
 
We have had "joke" reports of electrical "metaviri" (eg. "they
cluster around the negative terminal, so if you cut off the
negative post you should be safe ...", "they transmit over the
"third prong", but occasionally leak over onto the others ..."). 
However, there are also a number of reports that changing the
battery in a computer damages the CMOS.  This is probably
because no matter how fast you change the battery, there is a
loss of power during that time, and therefore the data is lost. 
Some computers do have a backup system that does give you about
10 minutes to change the battery, but by no means all.
 
Next week: the dreaded modem virus.
 
copyright Robert M. Slade, 1992   DEFMTH5.CVP   920105