Available IRQ lines under 386 UNIX and Multiport Async cards

[Robert Bradbury]

I have a 2 port async card which is flexible enough to allow it to be
configured as COM3 (IRQ2, port 338) and COM4 (IRQ5, port 238).  Now
the problem I'm having is that getting IRQ2 to work as an interrupt
line for UNIX running on an AT Bus seems to be tricky.

My AT&T ISDG manual for UNIX 3.2 (pg 3-45) says that interrupt 9 is wired
to interrupt 2 and interrupt 9 seems to use IRQ2.  It also says:
   "IVN2 is used to connect the second PIC; however, peripheral
    boards that use IRQ2 can still be used by configuring the device
    driver to expect IVN 9."

Well, I've tried setting intvec in asy/config to both 2 and 9.
I've also tried ttypatch -t2 -i2 -a824 and ttypatch -t2 -i9 -a824.
(ttypatch has to be modified to get it to accept interrupts 2 & 9).

None of these seem to allow me to get the port on IRQ2 to work.

I've successfully used boards on IVN9 with drivers using intvec=9.

Does anyone know what you need to do to use boards using IRQ2?
Is it possible to use both IRQ2 and IRQ9?
Is this something that can only work in UNIX 3.2 (not in ISC 1.0.6
or Microport 3.0)?

I'm looking for a 3-4 port card which uses dumb 82450 or 16450 UARTs
where individual ports can be configured for different IRQ lines and
ioports (or disabled entirely).  (You can view this as a slot shortage
problem where I want one card to give me DOS COM1-COM4 and UNIX tty00-tty03).

You seem to be able to get 2 port cards for $50-$70 but 4 port cards all
seem to cost $300+ and require special drivers.  I can't see why there
isn't a cheap dumb flexible multiport card.

Robert Bradbury
Oracle Corporation
(206) 782-9474                            hplabs!oracle!rbradbur