> The README file is contained below, and it appears to be a Berkeley
> style copyright for use in NetBSD, among others.

 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
...
 * 2. Redistributions in binary form must include information specifying
 *    that source code for the emulator is freely available and include
 *    either:
 *      a) an offer to provide the source code for a nominal distribution
 *         fee, or
 *      b) list at least two alternative methods whereby the source
 *         can be obtained, e.g. a publically accessible bulletin board
 *         and an anonymous ftp site from which the software can be
 *         downloaded.

That is not the "Berkeley copyright".  That prohibits someone from making
substantial improvements which they do not wish to supply in source form,
which is perfectly acceptable under the Berkeley copyright.