Quote Originally Posted by mister_e View Post
it's just too bad that it doesn't allow to open COM port > 15 or 16
To handle higher ports, use "\\.\COMnn" (where nn is the port number, in decimal) when you define the port using the API.

You can patch the MSCOMM32.OCX control to allow ports >COM10. Use a hex editor to search for 3D 10 00 and change it to 3D xx 00 (where xx is the new upper limit, in hex) - e.g. 3D FF 00. NOTE: This may not work with all versions of the OCX.
CAUTION: Make a backup copy before patching.

My memory has faded but I think some early versions of the OCX worked above COM10.