Comments on: Com ports. Endangered Species?

Question: Com ports. Endangered Species?

barc0001 — Mon, 28 Apr 2008 23:40:06 -0800

Looking for a *new* motherboard with more than one serial port onboard.

A project I'm involved with is dealing with a number of computers that need to hook to measuring equipment via serial ports, and the newer machines they've bought to replace the old boxes only have one serial port, and there are two devices that need to be hooked up simultaneously. But wait, there's more! It needs a USB cell modem hooked up for communication as well, and it's running a custom O/S that's really old, but well geared for the diagnostic software (Custom Linux, not Windows) that needs to run. A USB-to-serial converter is being used to run the second bit of equipment, but if that is in place, then the USB cell modem doesn't work, so the equipment can't report back to base. If the USB-to-serial converter's removed, the USB modem works fine, but there's no diagnostic data to report.

Ultimately, this problem would go away if I can only find a motherboard that doesn't cost a fortune (and even if it did, if it wasn't too LARGE a fortune we'd probably entertain it) that has 2 onboard serial ports. Does anybody know of one, and if so, who still makes 'em?

By: zsazsa

zsazsa — Mon, 28 Apr 2008 23:44:47 -0800

What about PCI serial cards?

By: wierdo

wierdo — Mon, 28 Apr 2008 23:58:26 -0800

Server board makers are your friend.

SuperMicro P4SBE with 2 onboard serial ports
or for something not already EOL:
SuperMicro P4SCA with SATA

Hell, even new C2D SuperMicro boards have 2 serial ports, although you might have to use up a card slot to get it, since one of them is probably just a header and comes with one of those brackets with a connector on it.

I know I've seen a few Tyan boards that do also, but I can't find one off hand.

By: Pronoiac

Pronoiac — Tue, 29 Apr 2008 00:14:16 -0800

In this instance, I think a USB hub would solve the problem.

By: barc0001

barc0001 — Tue, 29 Apr 2008 00:33:53 -0800

zsazsa, I'm going to give PCI serial cards a go as well, my only concern there is possible issues with drivers and port addresses (2F8, etc..). Wierdo, that's an excellent start, I'm going to see what pricing my local hardware guy can give me on those boards. Pronoiac, unfortunately a hub won't do anything useful in this case, the issue is being caused by the fact that both devices want to be on /dev/ttyUSB0 inside the OS, all a hub will do is allow more devices to be added to the system, but not on that address.

By: pharm

pharm — Tue, 29 Apr 2008 05:27:50 -0800

Sounds like a job for a mini-itx motherboard. Not super cheap, but one of these with the optional serial port module installed would give you the serial goodness you're craving, plus all the reliability advantages that a fanless system brings.

Or use one of these and wire up the COM port headers on the mainboard.

By: pharm

pharm — Tue, 29 Apr 2008 05:31:59 -0800

Or go really teeny with an EPIA NX: they've got two serial port headers on the board.

By: gjc

gjc — Tue, 29 Apr 2008 06:34:03 -0800

Agree with using an add-on serial card, and that it may not work due to hard-coded COM1 COM2 memory addresses.

Agree that many boards will have a second serial port available as a header on the board, you'd just have to buy one of these if the board doesn't come with it.

By: odinsdream

odinsdream — Tue, 29 Apr 2008 06:43:15 -0800

Are you sure your current motherboard doesn't have a connector for a second serial port? Check the manual. It may not have come with the cable necessary, but this can be found online or in a parts store. Many motherboards contain a small serial header that you can use to get your second serial port.