Tin whistle of which tone holes the player should cover. The most common format is a vertical column of six circles, with holes to be covered for a given note shown filled with black, and a plus sign (+) at the top for notes in the second octave. Tablature is most commonly found in tutorial books for beginners. The tonic solfa is found in Ireland and possibly Wales, especially in schools. Many schools have printed sheets with tunes notated in tonic solfa, although in Ireland more have teaching by note. With the availability of good standard notation tutor books, teaching is possibly
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