3 Apr
2003
3 Apr
'03
7:06 a.m.
Because they occupied an entire slot (out of 5 on the
PC), and other
companies sold "multifunction" cards that could use the same slot for
serial, parallel, clock, and memory. Most of those were marketed as SIX
functions - how many people remember what the other two functions were?
Originally, I think the extra 2 functions were _software_, not hardware
on the board. Something like a print spooler and RAM disks to use all
that memory.
Later on, multifunction cards often included a games port, floppy
controller, and sometimes even video (there was a very popular card in
the UK that contained 2 serial ports, parallel port, joystick port,
Hercules/CGA graphics, floppy controller and real time clock -- yes, on
one full-length board).
However, the IBM "Async" card could ALSO do current loop, which most of
the after market cards could NOT.
That's one reason that I grab them if I see them...
-tony