Program communicating via com ports in Windows XP (locking up system)

[Nemmeh]

Hey everyone,

I've got some XP systems in the office that utilize an older program. The communication between the host (server) system for the software package and the clients is based on com ports. While this seemed to work fine in older operating systems, there seems to be a problem with some computers using windows XP.

Does anyone know if there is anything special I can configure on an XP machine to make the com port communication more friendly? Basically right now, I have some systems that will slow to a complete crawl, basically lock totally up if they attempt to utilize the program. I do however, have other systems that work just fine even with them running Win XP.

Does anyone know if there may possibly be something with the chipsets and win xp?

I'm just looking for any ideas that you guys may have...

Thanks..

Nemmeh.

 

[Dug]

Delete your serial ports in device manager and reboot.
Windows will reinstall them.

 

[Smilin]

It's not THX testing equipment you're hooking up to by chance?

 

[VirtualLarry]

I don't know about XP specifically, but I know that normally, programs do not get direct hardware-level access to COM ports. That was one limitation that kept some serial-port IR remote-control software from working properly in W2K, that worked fine in Win9x. (Like the Logitech software included with the AST/Logitech OEM IR remote that's popularly sold as surplus around the internet.) In that case, installing the software doesn't cause W2K to lock up or anything, it just totally fails to communicate. Same with the software that I have for my serial-port PSX memory-card reader/writer device, and my serial port link-cable for my PDA.

I know that MS provided some sort of special work-around for some major mfg's fax software programs, to be allowed to bypass hardware security in NT/W2K and access the COM port directly, but I don't know how that is accomplished, or whether the OS actually specifically checks for the allowed applications in question, or what.

You might also try installing the "GIVEIO" or "NTIO" driver, and allowing access to the I/O port range used by the serial port that you want to use, that might also bypass the hardware-level security on the COM ports under NT-based OSes.

Perhaps Smilin can provide more details about this. Normally, a "properly-written" serial-port program will only access the serial port via the logical serial-port APIs in the OS, not directly via hardware. Most software that was originally written for Win9x or DOS, is not "properly written".

 

[Nemmeh]

The software is proprietary unforunately. Thanks for all the suggestions, I will try them out on the systems and do some research on microsoft's site.