Mark Willis wrote:

>  Some VGA cards REALLY don't like COM4 using IRQ02/09 much, so mainly
> I use just 3 COM ports.

  I don't think VGA cards use IRQ2/9.  I think it is a problem with port
address $2E8.  I'm still using this lightning-struck motherboard on
which any attempt to use COM3 *or* COM4 generates events on them
(presumably writes to the primary port address) in time with cursor or
mouse action on the screen.

  I initially thought this was a curious accident, but apparently it's
something much deeper.  If I'm *extremely* lucky, it may relate to a
BIOS mis-configuration and be fixable.  I saw something on the list
about this, but can't recall the details (such as they were).

>   LPT2:, 0x278, IRQ 05  (Cannot use with above Com3 mapping!!)

  Eh?  Just pull the IRQ jumper.  Not actually necessary even then,
because the parallel port definition (as well as the *original* serial
port definition, now lost in mediocrity) defines a tri-state control on
this IRQ.

  But it's never used in DOS or Windoze (AFAIK - I expect some comment
on this), so I can only presume you refer here to Linux machines?

> as Robin's Pentium has no LPT port due to second sound card so she can
> use Dragon Dictate,

  As above, I don't see the connection?

  The trick about COM3 and COM4 is to use IRQs 10 and 11, with IRQ12
allocated to the PS/2 mouse.  All my ISA net cards use IRQ5 and my ISA
sound cards use IRQ7.  Works for me!
--
  Cheers,
        Paul B.