PSI BOX Reference
Modes 1-6 & 8.
Mode 3.
_______
Function: Centronics input to RS232 output interface.
Use:
PSI connects RS232 printers and plotters to the
parallel printer port of any computer.
Example: HP laser printer to IBM PC parallel port.
Summary.
_________
The PSI BOX acts as a one way data converter reading
information from a computer’s printer port port and passing it
straight through to an RS232 serial printer or plotter. This is a
popular way of connecting the HP Laser Jet printer, via a buffer,
to the parallel port of a PC.
Data is received according to the Centronics input
handshake and output according to the RS232 output handshake.
In this mode no other sort of data transmission is possible. The
IEEE port is disabled and does not respond to any commands or
data.
If the Centronics input buffer of the PSI BOX becomes
full then it will keep the BUSY line high until the RS232 device
accepts data from the PSI BOX.
In Mode 3 the whole of the PSI BOX ram acts as the
Centronics input buffer.
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Chapter 6
