Specifications

Centronics Printer Interface
REGISTER DEFINITIONS/ADDRESSES
Printer Port registers are accessed at I/O addresses 0378h through
037Ah, with 037Bh unused. I/O addresses 037Ch through 037Fh
redundantly map addresses 0378h to 037Bh, respectively. Tables 9-2
and 9-3 show register definitions and corresponding addresses.
Table 9-2
Parallel Port Register Definitions.
REGISTER REGISTER BITS
Data Port PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0
(R/W)
Status Port BUSY ACK PE SLCT ERROR 1 1 1
(R only)
Control Port 1 1 1 IRQ SLIN INIT AUTO STB
(R/W) ENB
FD
Table 9-3
Parallel Port Register Addresses.
Register Address
Data Port (R/W) 0378h
Status Port (R only) 0379h
Control Port (R/W)
037Ah
9-5