Some manufacturers tried to beautify the ugly trapeze a bit, with varying success. The others (Hitachi, for example
) designed the winding to minimise torque ripple with the simple commutation available.
Now, of course, the situation is completely different. A typical $1 microcontroller has all the power and storage of a 1970s university computer. Using a technique called DDS
, a microcontroller can synthesize a perfect waveform to drive those motor coils. There really is no excuse not to.