Could not link DOS COM to Windows USB Serial Converter

[amott]

Hello, I'm hoping to get some help in regards to the issue in the title. I'm not very familiar with dos; I'm just trying to set up VDos for some people at my place of work. The issue is, when I attempt to link my USB to Serial Converter to a COM Port, it gives me the error message displayed in the title. Any advice?

[Jos]

Such a converter would present itself as COM1.

If COM1="COM1": in config.txt produces the error “Could not link DOS COM1to Windows COM1 (2), check the Device Manager on how the converter is presented to Windows.

Jos

[amott]

Hello, Thanks for your response.

So I correctly mapped it in the config file, but now when I attempt to run the program it says "Unable to open comm port. Status code: -14". Any suggestions?

[Jos]

Not really, does the program have an option to set the communication parameters?

Then check those, for instance that the hardware port is the standard 3f8h for COM1.
If interrupt driven communication is available, disable that.

If that doesn’t bring anything, eventually post the program and I’ll have a look.

Jos

[amott]

So unfortunately, the program we're trying to run is custom proprietary code, so I'm unable to share it. According to one of the developers though, the source code is hard coded to work off of COM1. I changed the COM Port for the USB serial device in the device manager and in the config file to work on COM Port 1, yet that error persists. I appreciate all of your help so far, is there anything else you could suggest? Thank you for your time.

[Jos]

You could do COM1=<some_existing_file>:.

vDos doesn’t mind what’s to the right of the equal sign, as long Windows permits/supports it with file operations.
The only difference will be the DSR signal of the (simulated) COM port is set if the file contains data.
So the error will most likely be the same.

Since the developers are still around, you could ask them what triggers the "Unable to open comm port. Status code: -14" error.

You could eventually also start vDos with the logging option (….vDos.exe /log).
If the generated vDos.log file contains a line "INT 0C => XXXX:XXXX", the program uses a interrupt driven serial communication library.
And vDos doesn’t support this type of communication.
Though that doesn’t really explain why that error is generated.

Jos

[amott]

Hello, thanks again for your suggestions.

[Jos]

Merely that the program comes with FPU emulation (INT 34-3D) code for if there’s no 'onboard' FPU present.

Jos

Edit: A confusing response: amott deleted most of his previous post, like the vDos log with no insights.

[amott]

I apologize, I'm not very familiar with any of this technology. Does the FPU relate to the Serial to USB?

[Jos]

No, a Floating Point Unit is for floating point calculations.

Jos

[amott]

I see, so there's not really anything useful in the log file I presume. Okay, thank you for your help, I'll see if I can find a solution through further troubleshooting.