Date   : Thu, 07 Apr 1983 20:16:00 EST
From   : Keith Petersen <W8SDZ@mit-mc.arpa>
Subject: ^P from software

One nice way of doing this is to implement IOBYTE.  You can then PEEK
and POKE at address 3 (the IOBYTE) to turn the printer/console on-off
at will.  This is much better than POKEing into the operating system.
There have been some articles on the subject.  One that I recall was
"Implementing the CP/M IOBYTE" in Microsystems magazine.  I don't
recall what the issue was, but maybe SLIBES at MC can help with that
information..