Main Control Function - OKIDATA OL400 Service Manual

2.2

MAIN CONTROL FUNCTION

2.2.01 General Information
The main control function controls the reception of data from the host interface, processes
command signals, processes the image signals, controls the printer unit, outputs data, and
controls the operation panel.
The main control function consists of the items listed below.
CPU 80186-8
Font ROM (512 kbytes)
Page buffer (512 kbytes)
DRAM controller chip (MSM73V007)
Print controller chip (MSM75HJ014)
Font controller chip (MSM60791)
Programmable I/O (82C55A-2GS)
Interface Control
Centronics Parallel Interface Board
RS-232C Serial Interface Board
Optional Font Card
Optional RAM
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Service Guide OL400
Chapter 2 Principles of Operation
Page: 13