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This article was posted to the Usenet group alt.hackers in 1995; any technical information is probably outdated.

Electronic Highway Signs

Article: 7616 of alt.hackers!!!uunet!!!marlowe
From: (marlowe)
Newsgroups: alt.hackers
Subject: Electronic Highway Signs
Date: 7 Apr 1995 05:22:24 GMT
Organization: Illuminati Online
Lines: 45
Approved: The Ghost of Profs Past
Message-ID: 3m2i6g$
X-Newsreader: TIN [version 1.2 PL2]
Status: RO

The highway near my house in Houston has just installed those electronic
highway signs that show up all over the country. To be precise, these are
permanent, tall, and have bulbs as pixels.

I drove past one the day after they were put up, and I could have sworn
it printed "Hi.   -- Sign." Shades of _LA Story_. I have decided
that it was printing "Highway Sign Test", but I misread it.

Still it has got me wondering, is there anyway to hack one of these? How
are they programmed. Others in town have highway conditions on them.
How to the official types communicate with the sign? Radio? Phone? Direct

Hacking one of these puppies would be a tremendous feat. Can you imagine
the sign printing, "Honk if you like to kill Bill G...General Protection


Physics classes at Rice University are conducted in small (200 seat)
ampitheatre. Despite the room's excellent acoustics, profs still use a
microphone and speaker system.

Thinking that it would be fun to hack the wireless mike, we decided to get a
transmitter to block the signal and override it with one of our own.
Needless to say, this failed. We could block the signal, but trying to
add ours to the wireless signal just caused horrible static.

After much thinking we settled on a brute force approach. We took the
output from the mike's receiver and rerouted it through a
small hole we found in the floor where the sink drain ran down into
the basement.

In the basement, we spliced a connector to this cable to a microphone of
our own. In addition, we added a volume control to the wireless mike.

By placing a camcorder to an inconspicous corner, we were able to
monitor what was happening in the classroom down in the basement.

We wanted to close captioned the class for the thinking impaired, but the
prof who would have thought it was cool died. I wish I had had a
recording of him teaching class. Could have created a great campus legend
of the haunted classroom.


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