All emulators supporting a video output include the option to dump (or save) that output to a file, using the following controls:
To save the screen output to a file press the diskette button (yellow ellipse) alternatively PC key F5 will do the same (both are only possible if one of the emulators is running). Default the file name 'screendump.x.png' (Portable Network Graphics Image) will be used where 'x' will count up from '1' for every new screen dump.
Type a different name in the filename field (orange ellipse) to change the output file name. To change the directory location of the output file (and/or also the file name) use the VideoDump button (blue ellipse) and select another directory and/or file in the file selector window that opens.
Default the file will be stored in the emulator directory (located in the application data directory, see Directory and File Structure).
To save a file of a different type than a portable network graphics image, change the extension to the desired type, the following types are supported: png (Portable Network Graphics Image), jpeg (JPEG Image), bmp (Bitmap Image) and pcx (Paintbrush Image).