Many years ago a friend showed me a small stepper motor (from an old Tandon 20MB hard disk drive) being controlled by two DIP chips, and working very nicely. I remember that one was the L293D dual H-Bridge, but can't recall what the other was, or find any reference that includes another chip typically used with the L293D. Sadly, my friend is no longer with us, so I can't ask him about this.
I believe the second chip had a similar part number to the L293, and was a standard chipset "companion" for it. IIRC, it would take 2 signals, Step and Direction, and generate the 4 phase signals needed by the L293.
Does this ring any bells?
Can anyone tell me what this second chip might have been?