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Re: Dual port serial card required

On Tue, Aug 22, 2000 at 06:32:39AM -0500, Andy Gardner wrote:
> In the past I've helped out a Net Cafe in a small town in Mexico get
> their dial-up going, so the local people don't get fleeced by the
> telco's.
> They were running 2 lines, but now need to expand. Problem is, we
> can't locate a dual port serial card locally, and they're not charging
> the sort of rate where they can go out and buy a Cyclades multiport
> card.
> Does any kind soul out there have a 2 port serial card with 16550's
> and the ability to use IRQs 5 and up, just lying around collecting
> dust.

i haven't got any spare serial cards, but i can recommend Moxa 8-port
dumb cards. i've used several and had no problems with any of them -
they just work out of the box.

you don't need an expensive smart serial card just to run a few modem
lines. any 486 or better is more than capable of driving dozens of dumb
serial ports at 115Kbps. even a 386 can do it.

they cost about $200 here (australian dollars.  $AUD1 ~= $US0.58) and
have eight 16550-equivalent serial ports on a single shared IRQ. they're
probably cheaper in the US where there's more competition for that kind
of thing.

they also have a 4-port card, but IIRC it wasn't significantly cheaper.
better value for money to get the 8 port.

no special drivers needed, the standard linux serial driver works (just
recompile the kernel to support more than 4 serial ports, create enough
ttyS* devices and configure the port IO addresses with setserial).

if that's too expensive, get a multi-function IO card. they usually have
2xserial, 1xparallel, IDE, and maybe a joystick port. set the jumpers to
disable everything but the serial ports and change the IO ports & IRQs
to avoid conflicts with existing hardware. check the doc for the card
before you buy it, not all will let you do this. a dirt cheap solution,
the only drawback is that it's not scalable - it uses one IRQ per port,
just like ttyS0 and ttyS1 built into the motherboard. not a problem if
you don't intend to have more than 4 ports. at a guess, $20 new or $5 on
a chuck-out table at your local computer shop or swap-meet.


craig sanders

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