I have an internal modem that I configure as COM4 with IRQ 3, but
when I insert that card into my DOS 5.02 PC, it shows up
as COM3, with IRQ3 and COM4's address (2E8)!

When I get into debug, and dump the data at 40:0, it shows
the address 2E8 as belonging to COM3 - even though the modem
should be at COM4.

Now, I know the modem is working correctly since I have tested
it in a different PC - and it shows up correctly as COM4, 2E8, IRQ3.

To make it work in the DOS 5.02 PC, I have to configure the
modem as COM3, 2E8, IRQ3---but though I have a comm program that
allows that, the FAX program that came with the modem does not work.
Anyway, I would like the computer to display the modem as it is set,
as COM4...
I did run a few diagnostic programs, and they did not help at all:
a few displayed the modem as COM4, and others displayed it as
being COM3.

I am not using Windows, this is just a DOS problem...Any help
or pointers appreciated....
For various reasons, I must have this modem work at COM4, thus
switching COM ports is not an answer...

(Last time I posted this, I did not get any DOS specific answer,
this time I have included all the specific information....please help!)

-----
Avinash Chopde
avinash@acm.org