Two more file formats

Another Spectrum version is available, this time for Opus Discovery disk in an OPD file.

And yet another cartridge version, this time for the Spectrum-based Alf (Эльф) game console in an ALF file. The game is modified so that everything can be controlled using just a console controller, and some texts are changed accordingly. It should also take advantage of possible console modifications for 128 KB of memory and the AY sound chip (including entering a high score name using the controller), but I can't test the upgraded console. Although the .rom or .bin file extensions are often used for ROM-based cartridge image files, I have also seen the .alf extension for Alf, which is useful in this case to distinguish it from other ROM-based devices (e.g. Interface 2 cartridges or alternative Spectrum ROMs) or generic binary files.