From the nimble fingers of Peter Bancroft (peter@...) (3/11/02 6:31 PM) came... >> The other thing that confused me is that the Stamp echoes even if it's >> powered off. I never would have expected that. The Stamp must have an >> internal loopback, I know it's not the KeySpan adapter. > > That's very puzzling. I've never met anything that loopsback when it is > off. It may be crosstalk in the cable. What happens when you pull the cable > out at the stamp end. If it eachos, it is definitely crosstalk. If it > doesn't then maybe the stamp needs some input pulldown/pullup resistors. > Don't assume that the stamp board is correctly designed. Of course, a "dead" (= no power) slab of silicon might not do what a "live" one is expected to do. In this case, the ESD (electrostatic discharge) diodes inherent in most line receivers will power on the interface chip (if not the entire Stamp module) and to find you characters echoed is not all that surprising... -- Ted Spencer -- Be Brave Stay Calm Watch for the signs