Waveform generating device for electronic musical instruments

A waveform generating device for electronic musical equipment, comprising:

• means for generating addresses consisting of an integral part and a fractional part each;
• waveform memory means for storing differences between adjoining samples of amplitude form a waveform for subsequent generation thereof;
• interpolation memory means for storing coefficients g.sub.i+mj which are given by an equation ##EQU4## where i=0, 1, 2, . . . m-1, and j=1, 2, . . . n-1, and where f.sub.i+mk denotes specific ones of a series of amplitude values f.sub.L (L=0, 1, 2, . . . mn-1) sampled from an impulse response characteristic of a low-pass interpolation filter at a frequency equal to "m" times a sampling frequency of said waveform, and "n" denotes the number of interpolation points;
• means for effecting a convolution operation using said differences read out in correspondence to the integral parts of said addresses and said coefficients read out in correspondence to the fractional parts of said adresses;
• means for accumulating said differences in the waveform;
• and
• means for summing a value resulting from said accumulating and a resultant of said convolution operation to obtain the amplitude of said waveform.