Visual Basic, -Problem- 16 Bit Comm Port Access in Windows NT

-Problem- 16 Bit Comm Port Access in Windows NT

Author	Message
Matthew Bednal #1 / 6	-Problem- 16 Bit Comm Port Access in Windows NT We have a package originally developed to run on Windows 95 / Windows 3.1 / WfWg which communicated with external hardware via the PC's serial ports. This has worked well in Win 3.11 / wfwg / 95 but attempting to use the software in NT causes problems. The software is coded in the current version of Visual C++, and we _have_ to use the comm ports via the WOW interface. We do not have the resources to re-code the applications for 32-bit operation and a large amount of the code is contained in VBXs. It appears that the comm port messages are being intercepted before our code sees them, so we are effectively missing the interrupt messages etc. for incoming data. Also, we have _Never_ been able to get COM1 to work on an NT 4.0 Workstation. We can find no apparent reason for this. So, the question, has anyone had any previous experience of this particualr problem? Or can you tell me a way to implement serial communications in NT4.0, without resorting to 32-Bit code (as we do not have the resources available to re-write the rest or our software). We have seen that some 16-Bit comms packages run by constantly polling the serial port, but we ideally do not wish to do this as it is a somewhat inelegant solution. (unless it is the only way). Any information on accessing the serial ports, in Visual C++, on NT Workstation will be gratefully recieved. I apologise in advance if my query is a little vague as i am carrying out these requests for my colleague who writes the software. If you have any queries or require any more information please email me at: Thanks Matthew Bednall
Fri, 06 Aug 1999 03:00:00 GMT

:^ #2 / 6	-Problem- 16 Bit Comm Port Access in Windows NT Quote: >We have a package originally developed to run on Windows 95 / Windows 3.1 / >WfWg which communicated with external hardware via the PC's serial ports. >This has worked well in Win 3.11 / wfwg / 95 but attempting to use the >software in NT causes problems. NT does not allow win 3.1,dos and win 3.11 apps to have direct access to the hardware. this is why dos games do not have sound in NT (eg. DOOM) dos drivers and windows drivers are not allowed to have access to the sound card,com ports,the video card etc. there might be a library available to allow a 16 bit program to access hardware in NT. I don't know of one, but i am sure someone has tried to solve this problem. Quote: >I apologise in advance if my query is a little vague as i am carrying out >these requests for my colleague who writes the software. If you have any >queries or require any more information please email me at: >Thanks >Matthew Bednall
Sat, 07 Aug 1999 03:00:00 GMT

Michael Spark #3 / 6	-Problem- 16 Bit Comm Port Access in Windows NT Quote: > We have a package originally developed to run on Windows 95 / Windows 3.1 / > WfWg which communicated with external hardware via the PC's serial ports. > This has worked well in Win 3.11 / wfwg / 95 but attempting to use the > software in NT causes problems. ... > Thanks > Matthew Bednall I've had a similar problem with a Win16 app not being able to access the comm port. Under Win95, I was able to use mkcompat.exe and fix the problem. NT does not have this, but I have heard that there is a similar utility for NT. Does anyone know the name of this utility and where I can find it? It must exist! Oh, please, exist! -Michael Sparks
Sat, 07 Aug 1999 03:00:00 GMT

William J. Keat #4 / 6	-Problem- 16 Bit Comm Port Access in Windows NT Quote: >>We have a package originally developed to run on Windows 95 / Windows 3.1 / >>WfWg which communicated with external hardware via the PC's serial ports. >>This has worked well in Win 3.11 / wfwg / 95 but attempting to use the >>software in NT causes problems. >NT does not allow win 3.1,dos and win 3.11 apps to have direct access to >the hardware. this is why dos games do not have sound in NT (eg. DOOM) >dos drivers and windows drivers are not allowed to have access to the sound >card,com ports,the video card etc. there might be a library available to allow This is not entirely true. I have several Win3.x apps that run perfectly under NT. Various communications programs can access COM ports, I have several Win3.x games that can use sound without any special drivers, other than those that came with NT. Why don't we find out what kind of access the program needs to have before writing it off completely. ******************************************************************************** * Opinions - Mine Only http://pages.prodigy.com/VA/wjake/home.html * ********************************************************************************
Fri, 13 Aug 1999 03:00:00 GMT

Larry Brasfiel #5 / 6	-Problem- 16 Bit Comm Port Access in Windows NT Correction below. Quote: > >>We have a package originally developed to run on Windows 95 / Windows 3.1 / > >>WfWg which communicated with external hardware via the PC's serial ports. > >>This has worked well in Win 3.11 / wfwg / 95 but attempting to use the > >>software in NT causes problems. > >NT does not allow win 3.1,dos and win 3.11 apps to have direct access to > >the hardware. this is why dos games do not have sound in NT (eg. DOOM) > >dos drivers and windows drivers are not allowed to have access to the sound > >card,com ports,the video card etc. there might be a library available to allow > This is not entirely true. I have several Win3.x apps that run perfectly > under NT. Various communications programs can access COM ports, I have > several Win3.x games that can use sound without any special drivers, other > than those that came with NT. Why don't we find out what kind of access the > program needs to have before writing it off completely. Actually, what Matthew asserted is entirely true. Those Win3.x games are using API's that are available on the NT WOW process. The COM ports are virtualized well enough that many serial communication programs still run. They are trying to access the serial port, but the attempt is trapped and the OS figures out how to achieve the same effect as if the access had been successful. But no hardware access is permitted to applications. That said, it may indeed be too soon to write off using that package on NT. -- -- Larry Brasfield The aforementioned views are mine alone.
Fri, 13 Aug 1999 03:00:00 GMT

paul huan #6 / 6	-Problem- 16 Bit Comm Port Access in Windows NT Quote: > > We have a package originally developed to run on Windows 95 / Windows 3.1 > / > > WfWg which communicated with external hardware via the PC's serial ports. > > This has worked well in Win 3.11 / wfwg / 95 but attempting to use the > > software in NT causes problems. > ... > I've had a similar problem with a Win16 app not being able to access the > comm port. Under Win95, I was able to use mkcompat.exe and fix the > problem. NT does not have this, but I have heard that there is a similar > utility for NT. > HHHHHH
Fri, 13 Aug 1999 03:00:00 GMT

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