Oki OKIPAGE 10i Service Manual page 22

The main control board consists of a single chip CPU, two program/font ROMs, four DRAMs, an
EEPROM, a host interface circuit, and a mechanism driving circuit.
(1) Single chip CPU
The single chip CPU is a custom CPU (32-bit internal bus, 32-bit external bus, 28.24-MHz clock, with input
frequency from a 7.06-MHz clock) which incorporates the RISC CPU and its peripheral devices, and has
the following functions:
Built-in device
Chip select controller
Bus controller
DRAM controller
DMA controller
Parallel interface controller
Serial interface controller
Video output port
LED STB output port
Timer
Serial I/O Port
I/O Port
(2) Program and Font ROMs
The Program and Font ROMs store the equipment program and various types of fonts. EPROM or Mask
ROM is used as Program and Font ROMs. The mounting locations of these Program and Font ROMs vary
depending on the type of the ROMs (for the mounting location see Section 7.4).
(3) DRAM
The DRAM is a 2MB resident memory on the main control board that stores edited data, image data, DLL
data and macro data.
(4) EEPROM
Service Manual - OKIPAGE10i
Chapter 2 Operation Description
Function
Control or ROM, RAM and I/O device
Transfer of image data from DRAM t video output port
Control of Centronics parallel interface
Control of RS-232C serial interface
Control of LED head
Generation of various control timing
Monitoring of paper running and paper size
Control of operator panel, EEPROM, and options
Input and output of sensor and motor signals.
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