🚀 go-pugleaf

I'm a good man <mfchan@netfront.net> wrote in article
<53dhsg$pvg@adenine.netfront.net>...
> I would like to have COM3 & COM4 w/ different IRQs from that of COM1 &
COM2.
> 
> Any suggestion or potential problems?

No cheapo serial port cards you can get in H.K. do 16-bit IRQs, except my
IT-PACK-5 ISA Super-IO card (which the manufacturer I think has gone busted
and I am not willing to part with mine).

The problem is to find 2 IRQs to fit your two comm ports. IRQ3 and 4 are
already taken for COM1 and COM2. IRQ6 I think is reserved for some special
stuff which I forgot. You are left with IRQ2, 5 and 7. IRQ7 is for the
printer port (for which you may choose to use a poll driver in which case
it would be free), 5 for the sound card, and 2 *may* be free, but as it
cascade to IRQ9, all sorts of problems may come up... Basically it's a
mess.

There are intelligent serial cards out there that has a CPU on it. While
they don't need IRQs and can support from 4 ports upto 100s of ports and
put much less load on the CPU, they are expensive. Another solution is the
Hayes ESP serial card. Again, no IRQ (I think), port speed could go up to
230Kbps (versus 115KBps of 16650) and have a bigger FIFO buffer. There are
2 comm ports on each card. I have no idea where you could get them in H.K.
or how much do they cost. Oh Win95 driver has just come out for it.

Cheers,
Frank.