Re: External vs. Internal Modems

[Ramon Gandia <rfg nook net>]

Ryan Ware wrote:
> 
> The only way you will need isapnp is if you get an ISA modem.  As for
> setup, I believe all you need to do is make a link called /dev/modem to
> the proper com port (/dev/ttyS0 or /dev/ttyS1), although I'm not
> completely sure for an external modem.  I have ISA.  Good luck.

You only need isapnp is your modem is internal, ISA and PnP
enabled.  Some, like the US Robotics Internal Sporster, have
jumpers:  COM1 com2 PNP etc.  If you disable pnp in the jumpers
then you do not need isapnp.

With a modem set with jumpers to a port, you need to go into
the BIOS and disable the motherboard port.

Example.  A USR Sporster internal. You set it for non-pnp on
COM2 (cua1).  Plug it in.  Restart the computer and go into
BIOS setup.  Look for the serial port configuration.  Typically
you will have two serial ports on the motherboard, called A and
B.  Usually A will be set to COM1, and B will be set to COM2.
Assuming this is the case, you go into port B setup and set
it to "disable".  That frees up COM2.  Or you could set up the
port to some different com port assignment.

With an external modem, you want to ENABLE the com port that
your cable attaches to, obviously.

Be forewarned about COM ports.  COM1 and COM3 share the same
interrupt (4), and COM2 and COM4 share irq 3.  The lower the
number of the interrrupt, the higher priority.  It is best
to give modems a fairly high priority as the data coming
down the modem cannot be 'put on hold', it just keeps streaming
in.  ON a pentium, this is not too critical.

COM4 (cua3) is a bad choice because video cards often use
the i/o space.  YOu never should use COM4/cua3 unless you are
sure your hardware lets you with no conflicts.  Some people
think they are okay, and they notice strange glitches later
on.

If you think PnP avoids all these problems, be assured that
there is nothing worse than a PnP situation that does not work
properly.  It can drive you to distraction because its like
nailing jelly to a try.  You fix THIS, and then THAT changes
or freezes the comptuer....  Jumpers  type of modem or an
external are best.



-- 
Ramon Gandia ================= Sysadmin ================ Nook Net
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