Bipolar stepper motors are common in printers. They are different from unipolar steppers. Bipolar steppers usually have four wires (while unipolar 5). Bipolar stepper motors can be driven by using H-bridge circuit like SN754410 from Texas Instruments.
One SN754410 IC can drive single bipolar stepper motor. In this example you may see two of them, so each motor is controlled via separate H-bridge IC. Whole circuit is built around Basic Stamp BX-24 which can be programmed by using Basic language. Sample source code is available for testing.