Specifications

ImageWriter II/L Basics - 9
CPU and Gate Array
The CPU (IC8) along with the gate array
(IC4), handles the logic and decision-
making of the printer. They combine to
evaluate the status of the printer and issue
commands concerning when to transfer
data, when to start printing, when to run
the motors, and what actually prints. All
the functions of the printer are controlled
by these two devices. The rest of the
circuits are supporting circuits.
Carrier Motor Drivers
The carrier motor circuit is made up of
transistors Q1, Q2, Q12, Q13 and IC1. The
transistors make up a circuit that is used as
common returns from the motor. The
transistors also supply the higher voltage
and current needed to drive the motor. IC1
is a transistor pack that completes the
drive signals circuit when turned on. Each
of the four signals drives a phase of the
motor. These drive signals go to the carrier
motor on the printer through CN2.