Specifications

ImageWriter II/L Basics - 8
ROM
The ROM (IC10) chip has the start-up
routines and several features such as
character sets and self-test routines built
in.
RAM
The RAM (IC9) is used in the transfer of
data and acts as a buffer. When printing
starts, the data to be printed is transferred
from the host CPU to the RAM on the
printer. From the RAM the data is passed
through the logic and sent to the print head
to print. Turning off the printer clears the
RAM.
Interface Circuits
The interface circuits (IC2 and IC3) on the
main board handle the data transferred
from the host CPU via the sub PCB board.
These circuits also handle the status and
control lines from the printer to the host
CPU.
Print Head Drivers
The print head drivers (IC5 and IC6)
process the print head drive signals from
the CPU and gate array. The signals are sent
to the print head board through CN5.