OldSalt1945:
I have a variety of Arduino computers and 4 L298N driver boards and 4 small four phase unipolar motor 24 V/75 ohms = 0.3 A.
Those unipolar motors can be controlled with half an ULN2803... However you
haven't said how many wires (6 or 8 I guess as you mention the H-bridge chip).
For driving several unipolars with ULN2803's you can connect 74HC595 shift
registers to drive the inputs of the ULN2803's, giving 3 pins for as many motors
as you want...