Abstract: A device for reading sound waveform data has a waveform ROM for storing waveform data represented as an amplitude in a time series. Sound waveform data is repeatedly read from the waveform ROM. The reading of a single waveform corresponds to a single period. A scale ROM stores a plurality of frequency dividing ratios. A programmable counter divides a signal having a predetermined frequency in correspondence with a frequency dividing ratio output by the scale ROM and outputing a clock pulse. A counter counts the clock pulses and indicates the addresses of the waveform ROM. The scale ROM changes the frequency dividing ratio data during an arbitrary divided period of intervals in the period for reading the waveform data. During the period for reading the waveform by the counters, the sound waveform read out has a single frequency and accordingly a single period. The waveform reading period is divided into m number of intervals.

Abstract: A sound generating device for generating a variety of sounds has a main control circuit which includes a ROM for storing melody data. A sound source is coupled to the control circuit in accordance with sound scale data stored in the ROM. The sound source has a waveform memory for storing a sound waveform in a digital form. The sound waveform memory is read at a frequency corresponding to the sound scale data. An envelope waveform memory stores an envelope waveform in a digital form. A digital to analog conversion circuit converts the digital envelope waveform in accordance with the digital sound waveform to produce an analog voltage.

Abstract: A device for reading sound waveform data has a waveform ROM for storing waveform data represented as an amplitude in a time series. Sound waveform data is repeatedly read from the waveform ROM. The reading of a single waveform corresponds to a single period. A scale ROM stores a plurality of frequency dividing ratios. A programmable counter divides a signal having a predetermined frequency in correspondence with a frequency dividing ratio output by the scale ROM and outputing a clock pulse. A counter counts the clock pulses and indicates the addresses of the waveform ROM. The scale ROM changes the frequency dividing ratio data during an arbitrary divided period of intervals in the period for reading the waveform data. During the period for reading the waveform by the counters, the sound waveform readout has a single frequency and accordingly a single period. The waveform reading period is devided into m number of intervals.