FWIW, I recommend picking up an inductive pickup audio tracer, often called a sniffer in the telecom field. Consider it an audio o'scope. Handy for tracing wires, checking CPU activity or watchdogging, audio circuits. Especially good for listening to DAC/Op-amp activity on vector boards. Brendan Keith brendan.keith@wilcom.com To UNSUBSCRIBE from techtoolslist, send a message with "UNSUBSCRIBE" in the message body to: techtoolslist-request@flippers.com. Please direct other questions, comments, or problems to jrr@flippers.com.