I run a prog (written in QBasic 4.5) which outputs to a comport under DOS without any problems. The same prog run under WFW 3.11 gives no output at the comport. Can anyone advise how to address the comports in WFW and/or how to determine the comport addresses in WFW. Yes, I have asked this question on other forums, including DOS and programming forums, without success. Thanks V...

Programs written for DOS assume exclusive use of ports. Windows programs use drivers that control the use of the ports. I thought there may be a setup option in Windows. Something about setting exclusive use. Otherwise goto DOS to run the application.

Thanks Wizard-Fred - yours is the most sensible response I've had in many months. Now to look for settings or mention of drivers. Thanks again V...

More info. Actually there was originally planned the use of INT 14, but it was so badly implemented that developers took to writing to the ports directly. One of the best sites for I/O processing is lvr.com. However, most of the stuff now is for new things, .NET and USB. Many links are available. Do you have the source of your QuickBasic 4.5 application? Does it have to write to the COMM port? The possible solutions are direct writing to the ports or installing somelike a API or DLL that will intercept and pass the signals through. Or there is the case of the big-rewrite. Or just get a stand alone DOS machine. (cheapest alternative)

Thanks again WF. Yes I have the source of the QB prog, I wrote it. The prog controls the keying of a a transmitter (ol' fashioned Morse code) so, yes, it does have to output to a Com or serial port which it does ok in DOS but just for the heck of it I want to get it operating in WFW. The 'puter I use is almost dedicated to this prog so it's not a b-i-g hassle but it annoys me that I cannot find the reason for not being able to run it in WFW. Cheers V...