On 28 Aug 98 at 10:10, Daniel Leung wrote:

> >I'm going to guess that the MoBo was recently changed and that they
> >left the original cables installed in the case. This same problem has
> >come up numerous times over the last 2-3 months. Each motherboard
> >has it's own unique pinout for the comm connectors on the board.

  There are two obvious/sensible ways to map a 9-pin serial connector
to a 10-pin header on the motherboard.  The problem is that the 9-pin
connector is numbered:

  1   2   3   4   5
    6   7   8   9

while a 10-pin header is normally numbered:

   1   3   5   7   9
   2   4   6   8  10

Some makers map pin 2 to pin 2, and some map it to 3 and map pin 6 to
2.

  [I have not seen any case where a maker has mapped the same
signals, from a 25-pin connector, to different pins on the header
than they use for the 9-pin connector....  Thankfully.]

  Neither of these is an official standard, and there are of course
several thousand other possibilities, which don't strike *me* as
obvious/sensible, but might happen to solve some design problem with
a specific board.

David G