PSI BOX Reference
Modes 1-6 & 8.
Mode 5.
_______
Function: A Centronics input to IEEE output interface.
Use:
PSI connects an IEEE output device to the
parallel printer port of a computer.
Example: HP 7475 IEEE plotter from printer port of a PC
running LOTUS 123, AutoCAD etc.
Commodore IEEE printer from PC printer port.
Summary.
_________
The PSI BOX acts as a one way data converter reading
information from a computer’s printer port and passing it straight
through to an IEEE bus output device.
Data is received according to the Centronics input
handshake and output according to the IEEE output handshake.
In this mode no other sort of data transmission is possible.
Talk Only Operation.
___________________
The PSI BOX can also be set to act as a Talk Only IEEE
from Centronics parallel input interface. To select the Listen
Only configuration set the Mode switches to Mode 5 and set the
IEEE address dip switches all upward ie address 15. Instead of
the PSI BOX becoming IEEE device 15 it will be in Talk Only
mode. Here the a controller instructs one or more devices to
listen, the PSI BOX will take data from its Centronics parallel
input buffer and send it to all the listeners on the bus. The
controller should not instruct any device other than the PSI BOX
to Talk.
In addition, the PSI BOX will happily Talk to a Listen
Only device, in a system without a controller, that does not
provide any addressing information.
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Chapter 6
