Hi.

My hat is off to you for some really good detective work there.  I'm not 
sure I would have had the ingenuity to figure out how to test that 
out.  Very creative.

73, de Lou K2LKK



At 10:16 AM 8/2/2007 -0500, you wrote:
>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
>
>
>
>--
>No virus found in this incoming message.
>Checked by AVG Free Edition.
>Version: 7.5.476 / Virus Database: 269.11.2/933 - Release Date: 8/2/2007 
>2:22 PM

Louis Kim Kline
A.R.S. K2LKK
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