REQ: Help opening COM1

**grepzen** · 04-21-2006, 07:53 PM

Some Vitals: VIA SP1300, XP Pro SP2, BR-355

Symptoms:
When the computer boots, Com1 is exists (in Device Manager) but any attmept to interface with Com1 yields: "Unable to open Com1".

If I open Device Manager, 'uninstall' then 'scan for hardware changes', the port is re.detected and functions fine. This happens w/ all software/apps which access com1 (Terminal, GPSGate, etc). This is also independant whether or not the serial GPS is plugged in or not.

Do any of you have any ideas/ solutions? Thanks for your time and effort.

Respectfully,

**tom61** · 04-22-2006, 10:17 PM

Probably the GPS drivers locking the port. Uninstall the GPS drivers and see if the problems continue. If the problems stop, see if you can find a different version of the drivers for GPS.

**nkotch** · 04-23-2006, 12:58 AM

Has it been working before and just started doing this? Have you recently enabled any other com ports in the bios?

**grepzen** · 04-23-2006, 06:38 AM

Tom61 :: I'm using iGuidance w/ a Serial GPS ant (BR355) there are no drivers as such. --other than the serial drivers from Microsoft as included w/ WinXP.

nkotch :: I had tried a few software comport splitters so that I could run multiple GPS apps from one GPS input (serial).
1) I've removed them from my systm,
2) I can't find any evidence (TaskManager/Processes(AllUsers)) that any of them (other than GPSGate) are running. BTW: the symptoms exist with or w/o GPSGate running.

Subsequent to my first post, I've disabled COM2 which is a blank header on the motherboard (nothing connected) & the symptoms remain the same. (prior to the symptoms, no BIOS changes had been made.

None the less, you raise a great point.

Thank you both for your time and input.

**nkotch** · 04-24-2006, 02:46 PM

No problem, dealing with something similar here. Using a VIA board with the onboard COM1 connector, with headers on the mobo for COM2,3,4, recently got the right cable and "activated" coms 2 and 3 in BIOS and now I get the same error when I try to use COM1 in windows, that it's in use....... so only thing I can think of is some sort of resource conflict but for now I'm just not using it.

**tom61** · 04-25-2006, 05:56 PM

Originally Posted by nkotch

No problem, dealing with something similar here. Using a VIA board with the onboard COM1 connector, with headers on the mobo for COM2,3,4, recently got the right cable and "activated" coms 2 and 3 in BIOS and now I get the same error when I try to use COM1 in windows, that it's in use....... so only thing I can think of is some sort of resource conflict but for now I'm just not using it.

IIRC, Com1 and Com3 use the same IRQ by default, so that can confuse software. If you reassign the IRQs for Com3 and Com4 to some that are unused in BIOS, that might clear it up.

grepzen, do you have IR/IRDA enabled on your motherboard? IRDA uses Com3 I believe on most boards, and that could cause the same IRQ issues I mentioned above.

**grepzen** · 05-03-2006, 06:48 PM

Tom, sorry I'm so late getting back to you... I've let this issue simmer for a bit hoping some define guidance would provide some light.

on my VIA sp13000, COM2,COM3, the parallel port and IR/IRDA are all disabled.
I'm gona remove widcomm and all other BT related drivers & hw to distill this some more.

**grepzen** · 05-03-2006, 07:18 PM

well... I removed widcomm v5.0.1.1200 &rebooted. ==same error.
in GPSGate it's "[2] Error comport does not exist."

I sure appreciate your time spent w/ this. hope we can find a fix.

**grepzen** · 05-03-2006, 08:03 PM

nkotch, i'm not married to COM1, i'll move some header-connectors and see if COM2 might have better performance.

I've posted this issue to Franson's GPSgate forum. --I know they're not the source of the issue.. but might have some ideas we've not yet explored.
also posted to the VIA SP forum as I'm kinda thinking this might be a hw/bios issue. again.. they might know something we've not yet covered.

I'll update when I know more. ---have I mentioned my gratitude for the efforts here yet? -grinz-

**Jahntassa** · 05-03-2006, 10:53 PM

Take a look in your device manager, at the 'Mice and other pointing devices' section. Do you see a 'Microsoft Serial Mouse' or anything that says 'Serial Mouse' in it?

If so, disable that, and I bet it'll work better.

If not, ha! I'm totally clueless. I know Win2k and XP will incorrectly identify a Serial GPS as a mouse.