I work at an environmental lab and we use a ICP trace analyzer instrument for our work. The instrument is hooked up to a very old CPU using windows 95 OS with 2 serial RS232 ports. The program that the ICP instrument uses is built in DOS and requires 2 serial cables to work properly. We had purchased a new machine equipped with a Pent4 HT @3.0ghz CPU with 1024mb ram. There was no serial port installed on the unit so we bought one and installed it as PCI device card. I performed a fresh install of the ICP program in dos and it seems to sorta work in windows XP --> direct emulation of DOS using NTVDM (virtual dos manager). The problem that i run into is that I believe the program will use both serial ports simultaneously thus causing one of the ports to not respond and eventually halting the instrument. I've been messing around with the com ports in windows xp; trying different com port configurations and then matching them up with the ICP program in DOS. I even turned off the UART FIFO option for buffers and reduced the baud rates down to a 300 just to test them out but still no go Anyone having this problem with connecting a device that requires 2 serial RS232 ports and getting em to work properly in windows XP? (also to mention it would have to work in DOS?)

Windows XP does not allow direct port access, unlike MS-DOS. You need to ask the Software Creator to write an update. As an aside Windows XP (aka NT5.1) like W2K and NT4, does not have any MS-DOS subsystem, NTVDM is a glorified Virtual Emulation. NTVDM = New Technology Virtual DOS Machine http://www.windowsitlibrary.com/Con... It may be feasible to use Virtual PC 2004 to install MS-DOS though: http://www.microsoft.com/windows/vi...

accessing the com ports in MS VPC & win 98 is no problem here ... but i have 2 on board com ports, idk if the emulation works with a pci add on card. Today's subliminal thought is: 'Calm down ... it's only ones and zeros.'

I'm not acquainted with HT processors, but as 1) NTVDM can well manage to access RS232 COM ports through standard legacy DOS code 2) It seems your old application connects to the COM ports on the PCI card I suppose the trouble may be due to HT behavior. So if there is a way to disable that option for the processor (e.g. in BIOS settings), that is worth to try.