Rose Electronics Porter - Manual (Page 17)

PORTER INSTALLATION AND OPERATIONS MANUAL
13
Configuration of Parallel Units
The Centronics parallel interface is usually implemented consistently; however there are
some variations. Three lines are used to implement the flow control part of the interface.
They are strobe, acknowledge, and busy. Most Apple computer parallel interface cards
do not implement the busy signal. Some Radio Shack printers do not issue an
acknowledge signal. Most other printers use both the acknowledge and busy. There is a
provision for the Porter to handshake with all of this equipment. Each port except the
master port may be configured to ignore acknowledge, busy, or both signals by sending
the proper format commands to the Porter. The settings made by these format
commands can then be made permanent by using the keep command.
The Porter factory set default is to require acknowledge and busy for each port. Refer to
the format command for further information.