I
NTERNAL
M
ODEM
I
NSTALLATION WITH
W
INDOWS
3.
X
6
Each COM port uses an interrupt request
(IRQ). An accessory uses an IRQ to get the
attention of your computer’s centralprocessing
unit (CPU) so that the accessory can perform
a task. The computer stops what it’s doing,
depending on the priority of the request, to
help the accessory perform its task. When two
accessories share an IRQ, it’s like two people
asking different questions in unison to a third
person. Just as the person being asked the two
questions cannot understand either request, a
computer can lock up or otherwise fail to
communicate properly with your modem when
there is an IRQ conflict.
KEY POINT:
Accessories cannot
share COM ports and should not share
IRQs. When accessories try to share
settings, they will either not work
properly or not work at all
.
3Com has set your modem to a default Plug
and Play setting which is ideal for Windows 95
users. In this configuration, the shunts used to
set your modem’s COM port and IRQ settings
are hanging from single jumper pins and will
not affect your modem’s settings. As a
Windows 3.x user, you need to run the
ComTest program (on the
Connections
CD)
to determine what settings your modem should
use.