Innocent TV Imprisoned Behind Mirror

After following along with all the Magic Mirror builds, [Troy Denton] finally caved in and started building one for his girlfriend for Christmas. These popular builds are all pretty much bespoke, and this one is no different.

mirror2His victim TV didn’t have the ability to be switched on and off by the Raspberry Pi using HDMI/CEC, so he came up with an alternative. He got a couple of opto-isolators and soldered one to the on/off button on the TV’s control board. The Pi didn’t know whether it was switching the TV on or off, it just knew it was switching it. To solve this, [Troy Denton] connected another opto-isolator to the TV’s LED, this one the other way around. When the TV is turned on, the Pi now detects it.

The enclosure is fabbed from 2×4 lumber, the mirror is one-way acrylic which runs somewhere in the $75-100 range for this 27-9/16″x15-1/2″ application. The top and bottom rails include lines of holes to encourage airflow to keep things cool. the face plate is picture framing which makes it easy to mount the mirror. An ultrasonic range finder finishes off the build and when someone stands in front of this magic mirror, the Pi senses it and turns the monitor on.

Included in [Troy]’s post are the Python code and shell scripts he wrote as well as a bunch of pictures of the build process. We’ve seen Magic Mirrors builds before, including some small ones. They’re a cool addition to the house and a fairly simple build.

33C3: Chris Gerlinsky Cracks Pay TV

People who have incredible competence in a wide range of fields are rare, and it can appear deceptively simple when they present their work. [Chris Gerlinksy]’s talk on breaking the encryption used on satellite and cable pay TV set-top boxes was like that. (Download the slides, as PDF.) The end result of his work is that he gets to watch anything on pay TV, but getting to watch free wrestling matches is hardly the point of an epic hack like this.

The talk spans hardware reverse engineering of the set-top box itself, chip decapping, visual ROM recovery, software reverse analysis, chip glitching, creation of custom glitching hardware, several levels of crypto, and a lot of very educated guessing. Along the way, you’ll learn everything there is to know about how broadcast streams are encrypted and delivered. Watch this talk now.

Some of the coolest bits:

  • Reading out the masked ROM from looking at it with a microscope never fails to amaze us.
  • A custom chip-glitcher rig was built, and is shown in a few iterations, finally ending up in a “fancy” project box. But it’s the kind of thing you could build at home: a microcontroller controlling a switch on a breadboard.
  • The encoder chip stores its memory in RAM: [Chris] uses a beautiful home-brew method of desoldering the power pins, connecting them up to a battery, and desoldering the chip from the board for further analysis.
  • The chip runs entirely in RAM, forcing [Chris] to re-glitch the chip and insert his payload code every time it resets. And it resets a lot, because the designers added reset vectors between the bytes of the desired keys. Very sneaky.
  • All of this was done by sacrificing only one truckload of set-top boxes.

Our jaw dropped repeatedly during this presentation. Go watch it now.

Retrotechtacular: Max Headroom Takes Chicago In Audacious TV Hack

Those of you with long memories and a compulsive TV viewing habit might remember [Max Headroom], a quirky piece of TV ephemera from the late 1980s and early 1990s. [Max] was a supposedly computer generated TV show host and VJ with a pseudomechanical stutter, a slightly blocky rendered head, and a moving background of rendered lines. He looks a little quaint for viewers with a few decades viewing experience of CGI, but in his day he was cutting-edge cypberpunk TV.

He also made unscheduled showings on two Chicago TV stations in an audacious hack that has never been explained and whose culprit has never been found.

The real [Max Headroom] (Fair use) Via Wikimedia commons.
The real [Max Headroom] (Fair use) Via Wikimedia Commons.
If you were a bored British teenager and future Hackaday writer vegging out in front of your parents’ TV on an April night in 1985, you’d have caught [Max]’s genesis. He strung upon us by rising out of a title screen full of static in the Channel 4 TV movie [Max Headroom]: 20 Minutes into the Future.

The plot is a trip in itself. An investigative journalist seeking to uncover the sinister owners of his network (they run speeded-up adverts with the unfortunate side-effect of causing overweight viewers to explode) is pursued, causing a road accident in which he is injured by a collision with a safety barrier. Hence the name: [Max Headroom]. The network try to cover it up by producing a computerized facsimilie of the reporter which turns out to be an embarassing failure. They scrap the computer and it falls into the hands of a pirate TV station operating from a decrepit campervan, the Alphabetti-eating proprietor of which turns the character it contains into a TV sensation. Meanwhile the reporter escapes, recovers, and prevails over the villains.

The [Max] character proved to be something of a hit, with a TV spin-off series, VJing, adverts, and more. But that wasn’t the whole story of his appearances, back to that unexplained hack of Chicagoland TV.

The Chicago fake [Max Headroom].
The Chicago fake [Max Headroom].
On the night of the 22nd of November 1987, viewers of WGN were watching a sports program when the screen went blank and they were treated to a few seconds of a slightly home-made [Max Headroom] dancing in front of  those trademark moving lines. A couple of hours later on WTTW a rerun of a [Doctor Who] episode was again interrupted with the same fake [Max], this time speaking for a while before, if his performance wasn’t already bizarre enough, being spanked by a woman whose face is off camera.

As a piece of television history it’s an intriguing mystery, though since so little is known about the mechanism through which it was achieved it hasn’t achieved the notoriety in the technical world that you might expect. The stations involved conducted full investigations at the time and failed to locate a culprit, perhaps they should have been looking for that old campervan with the antennae on its roof.

It is very unlikely that a similar stunt could be performed today, with entirely digital TV studios and easy access to encryption technologies for external links to transmitter sites. But in the 1980s a studio would still have been an analogue affair so there would have been more opportunities to insert an unauthorized feed. Next year sees the 30th anniversary of the event, it would be fascinating if the perpetrator would mark it by anonymously revealing how it was achieved. Of course, we’d love to hear how you would have done it in the comments below. Surely we have readers who are intimately familiar with the television broadcasting equipment of the time.

Below the break we’re showing you both fake [Max] intrusions into the Chicago airwaves. First is the short outing on EGN, below that the longer one on WTTV.

Continue reading “Retrotechtacular: Max Headroom Takes Chicago In Audacious TV Hack”

From CRT TV To All-In-One Console

When the Raspberry Pi first appeared there was some excitement among Raspberry Jam attendees at the prospect of a computer with a video output on a board small enough to be concealed inside a TV. But while the idea is a good one the prospect of poking around among the high voltages of an older CRT model has meant that surprisingly few such ideas turned into reality.

One person who made the idea into a reality was [Jon], who took a [Dora] The Explorer branded CRT/DVD combo in a fetching shade of red and turned it into an all-in-one retro console gaming system with an embedded Raspberry Pi.

nintendo-crt-tv-thumbnailThis is however not merely a Pi stuffed inside the rear casing with a few holes for cables, instead he took away the substantial part of the DVD mechanism and mounted his Pi safely in a plastic box. Some USB extension cables bring all four USB sockets to the front panel through the DVD slot with a bit of Sugru to hold them in place. An HDMI panel-mount extension goes to the TV’s rear connector panel, as does a power switch for the Pi which is wired to a USB charger mounted on a trailing mains socket inside the case. The composite video from the Pi is wired to the TV’s AV in video socket.

We don’t blame [Jon] for not looking at the TV’s power rails to find power for his Pi, though a TV of this recent age would have safely mains-isolated rails that’s still a task fraught with hazards. The resulting unit is a high quality retro console, and as a final touch he’s given it a Nintendo logo and some storage for his gamepads on the rear.

We’ve had a few CRTs with integrated computers before here at Hackaday, but not all have been as they seemed. This Pi for instance sat in a vintage Singer TV, but the CRT was replaced with a modern LCD. Our favourite though it this Chromecast driving a 1978 GE model.

Hackathon Alert: Clean Tech At TVCoG

At Hackaday, we get notified of a lot of the cool events going on in hackerspaces all around the world. We’d like to keep you informed too, just in case there’s something going on in your neighborhood.

So we’re going to start running a weekly column on Saturdays that groups together all of the upcoming week’s exceptional events and noteworthy gatherings. If your hackerspace has something going on, tell us about your event on or around the preceding Wednesday. We’ll see your space in on Hackaday!
Continue reading “Hackathon Alert: Clean Tech At TVCoG”

Transmitting Analog TV, Digitally

If you want to really understand a technology, and if you’re like us, you’ll need to re-build it yourself. It’s one thing to say that you understand (analog) broadcast TV by reading up on Wikipedia, or even by looking at scope traces. But when you’ve written a flow graph that successfully transmits a test image to a normal TV using just a software-defined radio, you can pretty easily say that you’ve mastered the topic.

9944491474271463115_thumbnail[Marble] wrote his flow for PAL, but it should be fairly easy to modify it to work with NTSC if you’re living in the US or Japan. Sending black and white is “easy” but to transmit a full color image, you’ll need to read up on color spaces. Check out [marble]’s project log.

Hackaday has another hacker who’s interested in broadcasting to dinosaur TVs: [CNLohr]. Check out his virtuoso builds for the ATtiny and for the ESP8266.

(Yes, the headline image is one of his earlier trials with black and white from Wikipedia — we just like the look.)

Hackaday Prize Entry: Bypassing TV Broadcasting Restrictions

It’s a common problem faced by TV viewers, the programming they want to watch is being broadcast, but not to their location. TV content has traditionally been licensed for transmission by geography, and this has sometimes put viewers at odds with broadcasters.

The viewing public have not always taken this restriction of their programming choice lying down, and have adopted a variety of inventive solutions with varying degrees of legality and success. Many years ago you might have seen extreme-length UHF antennas to catch faraway transmitters, more recently these efforts have been in the digital domain. It was said in the 1990s that Sky’s Videocrypt satellite TV smart cards were cracked because German Star Trek Next Generation fans were unable to buy subscriptions for non-UK addresses, for example. You can argue in the comments over whether [Patrick Stewart] et al being indirectly responsible for a decryption coup is an urban legend, but it is undeniable that serial smart card emulators and dodgy DOS software for Sky decryption were sold all over Europe at the time.

Modern-day efforts to break the geographic wall on TV broadcasting have turned to the Internet. Services such as the ill-fated Aereo and the Slingbox set-top streaming products have taken the TV broadcast in a particular area and transported it to other locations for viewing online. But they are not the only Internet self-streaming option, if the idea of paying a subscription or tying yourself to a commercial service does not appeal then you can build an off-air streamer for yourself.

[Solenoid]’s project is an off-air streamer using a Raspberry Pi 3 with a USB DVB-T tuner. It uses Tvheadend to power the streaming, and OpenVPN to provide security. His build logs detail his efforts to ensure that power consumption is not too high and that the Pi is not running too hot, and provides instructions on how to set up and use the software. It’s not an overly complex piece of hardware, but it could provide a useful service for any of you who wish to keep up-to-date with your home TV when you are off on your travels.