OKIDATA OKIPAGE 20, Руководство по обслуживанию

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Memory area Use MENU Expansion RAM
System area Working area used for the program Fixed Fixed
Raster buffer Stores converted bit image data Enable Expandable
Receive buffer Stores temporarily the data received from
the host interface Enable Expandable
Page buffer Adds print information to the analyzed
receive data and stores the resulted data. -- Expandable
DLL/macro buffer Stores soft fonts and macro data -- Expandable
Font cache buffer Stores bit map fonts generated by the font
rasterizer based on scalable font
information Enable Expandable
(4) EEPROM
The EEPROM has a 1-kbit capacity and stores the following data:
Menu data
Various counter data (page counter, drum counter, fuser counter, etc)
Adjusting parameters (LED head drive time, print start position, etc)
(5) LSI (LZ9FF22)
Built in device Function
Serial I/O port Control of serial interface between controller and 2nd tray, 3rd tray, Multi-purpose feeder
Control of serial interface between controller and Duplex unit
Motor driver controller Control of Hopping motor
I/O port Inputting of various sensor signals
Output of various control signals
(6) Host interface
Centronics bi-directional parallel interface
RS232C interface
OKI HSP interface (Option)
The single effective interface or the automatic interface select mode can be selected using the menu. If
the busy state of the printer continues for a long time period, the buffer near-full control releases the busy
status at constant intervals even if the host side is busy so not to cause the interface time-out at the host
side.
(a) Centronics bi-directional parallel interface
This is an interface conforming to IEEE-1284 and provides either of unidirectional and bi-directional
communications according to each of the following communication modes.
Compatibility mode - Unidirectional communications from the host to the printer.
Nibble mode - This mode transmits 4-bit wide data from the printer to the host. In this mode, each
1-byte data is transferred in the form of two nibbles using ERROR, BUSY, FAULT, and SELECT