This is the SN754410NE Quadruple Half-H Driver.
This driver is designed to run high-current/voltage (bipolar stepping motors, relays, etc…) loads in positive-supply applications, providing bidirectional drive currents up to 1A with voltages from 4.5V ~ 36V.
The Enabling Pins on this driver come in pairs. This means that 1,2EN are on the same pin and 3,4EN are on another pin. Turning these pins HIGH will result in activation of the corresponding drivers, and turning them LOW will deactivate the drivers.
One thing we really liked about this driver is, that while it is a Half-H, with the correct data inputs each pair can form it’s own Full-H reversible drive, useful for solenoids and motors.
Vcc1 is used as a separate supply voltage to minimized the power dissipation inherent to all Transistors.
Vcc2 is used as the supply voltage for output circuits.