19 May
2006
19 May
'06
1:38 p.m.
On Friday 19 May 2006 12:58 pm, Jules Richardson wrote:
Question on a local newsgroup about PC power supplies
and whether the -5V
rail is used any more, and it's prompted me to wonder what it was *ever*
used for?
Did the original IBM PC make use of -5V for any reason? Or is its inclusion
maybe a hang-up from earlier machines that used three-rail memory devices?
Far as I know, things that needed -ve rails (like soundcards, serial ports
etc.) all used -12V...
curious.
If I'm remembering right, the very earliest PC MBs came with 16 or 64K of
ram, and that 16K involved dynamic ram that used that PS voltage. I think
that the Apple II power supplies also provided a -5, as well. The only
other place I remember that being used was on some of the early eprom chips
and some CPUs like the 8080.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin