For a few years I have had a Vexta 5 phase stepper motor. At last I have suceeded in drviing it and half stepping it using a 555 (timer) and a 4017 (decade counter) The power to the motor is critical; too much and it resonates, too little it doesn't turn. I found that 5v was the optimum. In the half step setup one must use 15 diodes to stop the chip terminals from being shorted out. (not necessary in full step mode).
During the building of this project, I came across some chips (D5101 LC) I am including a picture for easy identification. Bojan, you are the electronics guru, can you i/d these 22pin chips?
I used to work for NEC :-)
Will ask someone, they keep documentation in Japan for couple of years after phasing out... no idea what they may be at the moment
