I need help on setting up Com ports on IRQs above 9. This should not be
a mystery, but I have had no luck in trying on and off over the past 3
months.
Here's the story: I have installed a 4 Serial port / 3 LPT port card in
the main P233 computer (WIN 98 booting to DOS). I disabled all the ports
in the BIOS (Com 1, 2 & LPT1). On the second computer, a P120 (DOS 6.2),
I have added a 2 Serial port / 1 LPT port card in it. Com ports 1 & 2 on
both computers are set to default addresses and IRQ's and work fine. I
assigned Com 3 to 3E8 & IRQ11, Com 4 to 2E8 & IRQ 10. These two ports
will not talk to the corresponding ports on the other computer via NA
network. If I reset the NA config for Com 1 or 2, the network works
fine.
I can use a DOS, Checkit program with a loop back plug, and all ports
test fine.
If I change Com 3 to IRQ 5, that port will work just fine. It appears
that as long as I am using IRQ's below 9, they will work.
Both cards are 16 bit ISA cards and have the correct jumpers to set for
IRQ's above 9. As described above, I have tried IRQ's 10, 11, 12 and
another I forgot. They will not work.
I feel certain that I have the card jumpers set properly. Setting the
serial port config (F4) is not rocket science, so I believe I have those
right. I have been thru the computer's BIOS and think everything is
either enabled or disabled correctly.
By using IRQs 3, 4 & 5, I can work the upcoming SS contest in the two tx
category (TNC, rotator & network), but with all my efforts, I cannot get
the last Com port to work!
The LPT ports have not been any problem. Both the keying and logic
control for switching of the antennas and bandpass filters work fine.
Any suggesting or ideas? I am stumped.
Ray,
N6VR
|