Oki PAGE 18, Service Manual, Page: 28 / 395

Memory area Use Memory capacity setting
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 stored
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
EEPROM has a 16-kbit capacity and stores the following data.
Menu data l
Various counter data (page counter, drum counter, fuser counter, etc.)
l
Adjustment parameters (LED head drive time, print start position, etc.) l
(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 drive controler Control of Hopping motor
I/O Port
Inputting of various sensor signals
Outputting if various control signals
(6) Host interface
This printer has the following interfaces to the host.
Centronics bidirectional parallel interface l
RS232C interface l
OKI HSP interface (Option) l
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 bidirectional parallel interface
This is an interface conforming to IEEE-1284 and provides either of unidirectional and bidirectional
communications according to each of the following communication modes.
Compatibility mode l
Unidirectional communications from the host to the printer.
Nibble mode l