Brett Winches writes:
> Does the drake have a hand held remote control like the 71 does?

	I don't know, but that turned out to be a real learning
experience for me in the mid eighties.

	At that time, I wanted to see if I could make an Apple
II computer control the ICR71	. I built a photo cell circuit
so as to be able to turn the IR flashes in to something the
Apple II could read. I then wrote a timing program in assembler
that counted processor cycles and waited for the infrared signal
to go off if it was on or on if it was off. it would store the
count in a table.

	I thought I had figured it out and even wrote a table of
values for each button press on the remote.

	I wrote another assembler program to toggle one of the
game paddle bits on and off in the Apple and fed that signal to
a driver feeding some infrared LED's  I had scavenged from a
defunct TV remote.

	To make a long story short, it didn't work at all and I
was mystified.

	Then, I thought that there might be a carrier on those
data which was too fast for the 1-MHZ processor on the Apple to
follow.

	I remember taking that ICR71 receiver, connecting the
antena  input through a capacitor to the collector of the photo
transistor and tuning around 100 KHZ while hitting buttons on
the remote.

	Sure enough, I heard bursts of carrier about every 33
KHZ and I realized that IR remotes use a carrier and then gate
that on and off with lower-speed data.

	I couldn't make the Apple II get the timing right to do
the 33 KHZ carrier, so I built a 33-KHZ generator using a
crystal and some divide-by counters to get the frequency down to
33 kilohertz.

	When I ran the control program I had written on the
Apple and had it modulate that carrier, it did work.

	For a while, I had the Apple II set the R71 to 9.580
megahertz every Sunday morning and turn on a cassette recorder
to get the Radio Australia DX program which they used to have.It
all actually worked pretty well after I learned how infrared
remotes work.

	Of course, each manufacturer has its own pulse code and
carrier frequency so each new remote is a new project.

Martin McCormick WB5AGZ  Stillwater, OK 
Systems Engineer
OSU Information Technology Department Network Operations Group