ZiLOG System 8000 Hardware Reference Manual

HRM
Zilog
HRM
For either a Data Products or Centronics interface, connect
Jumpers E13 through E18 as follows:
CENTRONICS INTERFACE·
E13 to E14
E17 to E18
DATA PRODUCTS INTERFACE
E14 to E15
E16 to E17
4.5.1.1 I/O Bus: The CPU board I/O bus connects the System
8000 with the outside world. All devices that control both
the serial and parallel I/O are on the CPU board; function-
ally, these devices form eight serial I/O channels and two
parallel I/O channels. The serial channels support the RS-
232C
standard and the parallel ports can be configured for
either the Data Products or Centronics standard. One paral-
lel port, Port B of a Z80-PIO, is the data-out port; port A
handles status and control information. Table 4-6 lists the
control signals for the parallel printers. Table 4-7 lists
the status signals for the printers, and Table 4-8 lists the
data output of port B.
Table 4-6 Parallel Printer Output
Control Signals, Port A
BIT
NUMBER
CENTRONICS
DATA
PRODUCTS
0
Data strobe\
Data strobe
1
not used not used
2
not used
not used
3
not used
not U'sed
Table 4-7 Parallel Printer Input
status Signals, Port A
BIT NUMBER
4
5
6
7
4-12
CENTRONICS
Busy\
Select
Fault\
Acknowledge\
DATA PRODUCTS
Busy\
Online
Interface Valid
Data Demand
Zilog
4-12

ZiLOG System 8000 Specifications

General

Brand	ZiLOG
Model	System 8000
Category	Desktop
Language	English