OKIDATA OKIPAGE 20, Service Manual

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signal leads. This mode can provide the bi-directional operation in combination with the compatibility
mode.
ECP mode - This mode provides the asynchronous bi-directional interface and transmits and receives
1-byte data using eight data signal leads under the semi-duplex control by the host.
When the power is turned on, the compatibility mode is automatically selected. The change to another
mode from the compatibility mode is made through negotiation. (When the BI DIRECTION is set to
ENABLE in the menu, this change can be performed.) (For the electrical/physical characteristics of this
interface, see APPENDIX B)
(b) RS232C serial interface
The following protocol is supported for the serial interface conforming to EIA RS232C.
READY/BUSY (DTR HI or DTR LO)
X-ON/X-OFF
RBST X-ON
(For the electrical/ physical characteristics of the interface, see APPENDIX B)
(c) OKI HSP interface (Option)
This interface (slot) is an OKI proprietary universal interface that provides the platform to connect various
boards (including those supplied by third party vendors) such as the LAN connection expansion board and
SCSI expansion board. Any expansion boards compatible with this interface can be mounted on the
Control board in the piggyback connector without modifying the program at the printer side. The
conceptual diagram of the OKI HSP interface is shown in Fig. 2-2. (For the electrical/physical
characteristics of the OKI HSP interface, see the OKI HSP interface technical manual.)
(7) RAM module
Pin layout
Basic specification