OKIDATA ML393C Plus, Руководство по обслуживанию

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Service Guide ML393/ML393CPlus
Chapter 2 Principles of Operation
2.1.04 Interface Control
The printer is capable of serial or parallel operation. The desired interface method is selected by sliding
the interface cover to expose the desired connector. When this is done, the interface select switch is
turned ON or OFF to inform the Interface Control LSI (Q12) of the selected interface.
Parallel Interface
When the interface select switch is turned OFF, the parallel interface is selected and the Interface Control
LSI is in the parallel mode.
The data from the interface is received through connector (CN-1) and the Interface LSI (Q12) latches this
data to the internal register in the LSI at the rising edge of the STB-N signal.
The BUSY signal is turned ON as the data is processed. When processing is completed, the BUSY signal
is turned OFF and an ACK signal is sent to the host to request more data.
The BUSY signal is also turned ON when the printer is not able to receive data (buffer is full, printer is
deselected or an error condition exists).
RS232-C Serial Interface
When the interface select switch is turned ON, the serial interface is selected and the Interface Control LSI
is in the serial mode.