Lamzdeliai and twisted off of the wood. The blowing end is closed off with a stopper made from the wood, with one side cut off. At the place where the stopper ends, a whistle hole is cut into the bark, and one end of the hole is bent slightly inwards. Three to six finger holes are cut in the pipe. Wooden pipes are made of ash or linden wood. The bark is removed, and the instrument is hollowed out by burning, drilling or carving. The blowing hole, whistle hole and finger holes are made in the same way as for the
Pennywhistle modem acoustic coupled modems, the Pennywhistle design was dominated by the two large rubber cups on the top of the device that were used to hold the handset of a standard Western Electric phone. The Pennywhistle had a "step" cut into the front of the case where the various control switches were located, and the RS-232 port projected directly out of the front of the case. Pennywhistle modem The Pennywhistle was an early acoustic coupler modem originally designed and built by Lee Felsenstein in 1973, and later commercialized and offered for sale in 1976. It was one of the earliest modems