I am sure most people were already aware of this, but thought I would
mention it for those that didn't:
The cassette port has a single relay used to control the remote input on
a tape recorder. This is a fairly low current relay. It controls the
voltage to the motor in a tape player/recorder acting much like a pause
button.
Since it is fairly low current, you probably wouldn't want to use it
directly, but what can be done is to use it to drive another larger
relay. It is perfectly capable of driving the coil of another relay.
This gives you a simple real-world interface already built in.
The circuit is really simple for those handy with electronics. But for
those that need more information, there is actually an article in the
January 1989 issue of Portable 100 (page 6) which gives the details and
programming information.
I am soon putting together a simple example of controlling 8 and 16
relays from the printer port. Nothing fancy, but if there is interest in
the details for it, let me know.
Other mods I have been talking about are waiting for a few more parts
(shipping has been VERY slow lately) so that I can get in there and just
do it all at once.
