To run the ETI 660 emulator at least the ETI 660 system ROM files should be specified in the 'ROM' field. Default ETI 660 ROM location is the Eti directory (located in the application data directory, see Directory and File Structure) and the default filename is 'eti-660.bin'. To change the location use the 'ROM' button to browse for the file, do the same to change the filename or type in a new file name in the text field.
The binary, Intel hex and RCS Elf Emulator hex format are supported.