[sparky]

The comments, mostly. For example:

    object objects[69];				/* Don't know how many... */
    
    /* This report a sucessful breakin by sending a single byte to "128.32.137.13"
     * (whoever that is). */

    /* This appears to be a structure unique to this program.  It doesn't seem that
     * the blank slots are really an array of characters for the hostname, but
     * maybe they are.
     */

    /* There are pieces of "stub" code, presumably from something like this to
       get rid of error messages */

[percept]

>>(whoever that is)

Berkeley, apparently.