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9. CENTRONICS PRINTER INTERFACE
The bidirectional printer interface fully supports a Centronics-compatible printer. The
Centronics interface is available through the J1 connector. Refer to the table
"
J1 Peripheral Pinout
" in Appendix B for the connector pin assignments.
PROGRAMMABLE REGISTERS
The following topics illustrate the programmable registers for the Centronics printer
interface.
Line Printer Data Register
Register: Line Printer Data
Address: 378h
Access: Read and Write
D7
D6
D5
D4
D3
D2
D1
D0
7
6
5
4
3
2
1
0
Line Printer Data Register
Line Printer Status Register
Register: Line Printer Status
Address: 379h
Access: Read
BSY ACK
PE
SEL
ERR
IRQ
1
1
7
6
5
4
3
2
1
0
Printer Interrupt
0 Printer acknowledged
1 Read from status port
Printer Error
0 Active
1 Inactive
Printer Select
0 Off line
1 On line
Paper Empty
0 No
1 Yes
Printer Acknowledge
0 Ready to receive
1 Not ready to receive
Printer Busy
0 Yes
1 No
Line Printer Status Register