Centronics Printer Interface
Data Port
The Data Port register is an 8-bit bidirectional register with an output
control signal LPTOE* at connector J6, pin 10. When LPTOE* is
active (low), the Data Port is an output port; when LPTOE* is
inactive (high), the Data Port is an input port. There is a 470
Ω
pulldown resistor on LPTOE* to bring it low when it is not driven at
connector J6, making it an output port. The optional ZT 90039 cable
for the printer ties LPTOE* to ground so that it may remain
configured as an output port.
When the Data Port is configured as an input port, the data read in
reflects the data on the signals PD0-7 connected to the J6 data pins. If
any signals on the J6 data pins are left open, the data read in from the
port reflects the data written previously to the output data register.
9-6
Содержание ZT 8809A
Страница 15: ...Tables Table B 9 J5 Pin Assignments B 17 Table B 10 J6 Pin Assignments B 18 Table B 11 J7 Pin Assignments B 19...
Страница 334: ...Jumper Configurations W49 W48 A W47 B A B W37 W66 A W50 B C J7 W67 Figure A 11 W37 W47 50 W66 W67 Jumper Blocks A 34...
Страница 346: ...Jumper Configurations W61 W60 W62 W63 W64 A B A B W65 Figure A 13 W60 W65 Jumper Block A 46...