Parallel Interface; Bidirectional Parallel Interface (Ieee1284); Compatibility Mode (Host Printer Communication : Centronics Compliant); Reverse Mode (Printer Host Communication) - Citizen CBM-1000 User Manual

6. PARALLEL INTERFACE

6.1 Bidirectional Parallel Interface (IEEE1284)

6.1.1 Compatibility Mode (Host
Centronics compliant)
• General description
This printer provides Compatibility Mode, which specifies the Centronics
interface conventionally used for a wide variety of applications.
• Specifications
Data transfer method:
Synchronizing method:
Handshaking:
Signal level:
6.1.2 Reverse Mode (Printer
Data transfer from the printer to the host computer is conducted in Nibble or Byte
Mode. (For details, See "APPENDIX 2. BIDIRECTIONAL PARALLEL INTERFACE".)
Outline
The reverse mode has been devised to handle data transfer from an
asynchronous printer controlled by a host computer.
In Nibble Mode, data is transferred, 4-bits (A nibble) at a time, using traditional
control lines. In Byte Mode, data is transferred by making 8-bit data lines bi-
directional. Note that either mode cannot work simultaneously with Compatibility
Mode, thus resulting in half-duplex transmission. (For details, See "APPENDIX 2.
BIDIRECTIONAL PARALLEL INTERFACE".)
8-bit parallel
Controlled by nStrobe signal externally supplied
Handled by nAck and Busy signals
All signals are TTL compatible
Host communication)
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Printer communication :