DL4YHF's Amateur Radio Software:
A DLL Interface for Spectrum Lab

Last updated: March 10th, 2001.

Main Site: www.qsl.net/dl4yhf

DLL interface for digital communication modes

Note: This project is no longer supported ! Maybe the DLL interface will be updated in future, but due to a lack of interest there is no work going on at the moment.

To ease the implementation of new communication modes, Spectrum Lab had an open DLL interface. From the user's point of view, it works like this:

  • Get a DLL (dynamic link library) from someone with a new promising digital communication mode which shall be tested 'on air'
  • Start Spectrum Lab, activate the digimode-terminal,
    (or start another terminal program which uses the DLL interface)
  • Select the DLL as a 'new communication mode'. The DLL will now be loaded (dynamically).
    Text entered in the "TX window" will be passed from the terminal to the 'digimode DLL'. Some routines in the DLL turn the characters into audio data (modulator), which will be passed back to the audio-processing routines in Spectrum Lab. The generated audio may be sent out via sound interface or analyzed with the spectrum analyzer (or whatever possible).
    Received signals will be passed to the digimode DLL, which decodes them into characters. The characters appear in the "RX window" of the terminal.

That's just the basic concept. The digimode DLLs can be implemented in any programming language which is capable to generate DLLs for Win95/98 etc.
An author of a digimode DLL does not have to know how Spectrum Lab (or a compatible terminal program) works internally, and vice versa the author of Spectrum Lab (or a compatible terminal program) doesn't need to know anything about how the new transmission mode. This is  a big plus for many reasons !

Detailed information can be found in the following documents:

digm_dll.txt (a textfile explaining the 'digimode DLL' interface)

digmdelp.zip (a DLL skeleton for DELPHI programmers)

digmcpp.zip (a DLL skeleton for C++ programmers)

If you plan to use the DLL interface in your own program, send me an email to make sure you have the latest interface documentation and demo sources, because I don't upload them after minor changes.

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