Ieee 1284 Parallel Interface - Epson TM-T88IV Technical Reference Manual

IEEE 1284 Parallel Interface

Modes
The IEEE 1284 parallel interface supports the following two modes.
Mode
Compatibility mode
Reverse mode
Compatibility Mode
Compatibility mode allows data transmission from host to printer only: Centronics-compatible.
Specification
Data transmission
Synchronization
Handshaking
Signal levels
Connector
Reverse communication
Reverse Mode
The transfer of status data from the printer to the host proceeds in the nibble or byte mode.
This mode allows data transfer from an asynchronous printer under the control of the host. Data
transfers in the nibble mode are made via the existing control lines in units of four bits (a nibble).
In the byte mode, data transfer proceeds by making the 8-bit data lines bidirectional. Both modes
fail to proceed concurrently in the compatibility mode, thereby causing half-duplex
transmission.
86
Communication direction
Host → Printer communication
Printer → Host communication
8-bit parallel
Externally supplied STROBE signals
ACK and BUSY signals
TTL-compatible connector
ADS-B36BLFDR176 (HONDA) or equivalent product
Nibble or byte mode
Other information
Centronics-compliant
Assumes a data transfer from an
asynchronous printer