To run the Cosmac Vip emulator at least the Cosmac Vip system ROM file should be specified in the 'ROM' field (orange ellipse). Default Cosmac Vip ROM location is the Vip directory (located in the application data directory, see Directory and File Structure) and the default filename is 'vip.rom'. To change the location use the 'ROM' button (yellow ellipse) to browse for the file, do the same to change the filename or type in a new file name in the text field (orange ellipse):
The binary, Intel hex and RCS Elf Emulator hex format are supported.