OKIDATA Okipage 16n, Руководство по обслуживанию

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Operation Description 2 - 3 OKIPAGE 16n
Service Manual, P/N 59274401
Built-in device Function
Chip select controller Control of ROM, DRAM and I/O device
Bus controller
DRAM controller
DMA controller Transfer of image data from DRAM to OST LSI
Parallel interface controller Control of Centronics parallel interface
Timer Generation of various control timing
Monitoring of paper running and paper size
Serial I/O port Control of operator panel, EEPROM, and options
I/O port Inputting/outputting of sensor, signal and motor signal
Option I/O interface Control of OKI HSP interface
2.1 Main Control Board (BOARD-COM)
The control board consists of an one chip CPU, LSIs, program/font ROM's, DRAM's, an EEPROM,
a host interface circuit, and a mechanism driving circuit.
(1) One-chip CPU
The one-chip CPU is a custom CPU (32-bit internal bus, 32-bit external bus, 32-MHz clock)
that incorporates an RISC CPU and its peripheral devices, and has the following functions.
(2) Program/font ROM's
The program/font ROM's store the HP IV emulation program and various types of font.
MASK ROM is used as the program/font ROM's.