musical box

9-30 — elektor september 1980 musical box musical box As can be seen from figure 1, the actual melody generator is a single IC (IC4). It is the AY-3-1350 from General Instrument Microelectronics, a company with an excellent name for solid state musical devices. The circuitry around IC4 generates the clock signal, selects the melody required and amplifies the output level. To select a particular tune, one of the connections marked A ... E will have to be grounded and pin 15 of the melodic chip must be connected to one of the points marked 1 ... 4. There are several ways in which the desired code can be presented to the IC. One method is to use wire links, another is to incor- porate switches and a combination of the two is also possible. The printed circuit board has been designed to accomodate either of the two methods shown in figure 2. If the circuit is constructed exactly as shown in figure 1 and wire links are placed between points K . N and R . . . V (see figure 2a), the fo...