So far all I've found on the tapes are the Tape MERGE binary, the Unsigned Add binary, and the Frequency Counter binary. All work - the frequency counter is very fast at recognizing the freq, goes from 10Hz to 6mHz. Neat! I still have no idea how to transfer any binaries out the RS-232 port, although reading the Utility Programs User Manual (9000A-910) it does say "A binary program is compiled on a host computer and then downloaded to the 9010A/9005A, using the AUX I/F function. A binary program can be read/written from and to the cassette tape just like other programs. It can be uploaded/downloaded to or from a host computer and is executed in the same manner as other programs (including use as a subroutine of another program)." I suspect it is an obvious function that I just have't caught - the upload/download via the RS-232, but not yet... John :-#)# How to subscribe or unsubscribe from the list: To do either you send email to "MajorDomo@flippers.com" and in the body you state either "Subscribe techtoolslist" or "Unsubscribe techtoolslist", note that the Subject is "" (Blank)...