Hacklet 88 – Projector Projects

Everyone loves a big screen TV. Back in the old days, anything over 27 ” was considered big. These days if you’re not sporting at least 50″, you’ll end up with display envy. One thing hasn’t changed though, those who want to go really, really big get into projectors. Hacking and projectors seem to go hand in hand. Anyone else remember those old DIY projection setups where the user would put their TV in a box upside down? This week’s Hacklet is all about projector hacks!

hushWe start with [Chaz] with Projector Hush Box . [Chaz] had a good projector, but still found himself with a problem. Projectors generate a lot of heat, which is dissipated via a fan. For whatever reason, projector companies seem to pick the loudest fans available. [Chaz’s] solution is to put the projector inside a box. Done right, this makes for a quiet projector. Done wrong, it makes an oven. [Chaz] projector hasn’t caught fire yet, so we think he did it right. Two quiet and efficient PC fans direct air through the box, and around baffles which keep the noise down. An anti-reflective coated glass window lets the light out but keeps the noise in. Sound deadening foam helps cut the sound down even further.

led-projNext up is [ric866] with 100w LED projector conversion. The killer with projectors these days are the bulbs. In some cases it’s more cost-effective to buy a new projector than to replace the bulb in an aging one. That’s how [ric866] ended up with a pair of old NEC projectors – one with a working bulb, and one without. Bulbs for this model aren’t cheap at £100. [ric866] found a cheap replacement in a 100 Watt LED. The LED in question only cost £8.99 from everyone’s favorite auction site. LEDs may be efficient, but anyone who’s played with powerful LEDs can tell you they still get hot. [ric866] had to cut up the projector’s case a bit to fit in a heat sink and fan. He also had to spend some time bypassing the various case interlock switches. The final products color calibration looks to be a bit off, but not too shabby for a quick mod!

baffle[Tom_VdE] is serious about recycling. He isn’t one to let an old laptop go to waste when it can be turned into a projector! Remember the “TV in a box” kit we mentioned up in the title? This is the modern version of that same idea. [Tom] tore down the laptop’s LCD and placed it in a CRT monitor case with the appropriate lenses. A setup like this needs length, and focus adjustments. [Tom] managed all that by building a collapsible baffle out of plywood. A build like this needs a lot of light, so [Tom] is using a 100 Watt LED (or two). A water cooling system will keep the LED’s from melting down. [Tom] is still in the prototype phase, but we can’t wait to see his first movie night with this upcycled laptop.

sensorcalFinally, we have [Alex] who built Automatic projector calibration, project #161 on Hackaday.io. [Alex] took his inspiration from [Johnny Chung Lee] to build a system which can map a projector to any angle, size, or position. The secret is phototransistors embedded in the corners of a rectangular piece of foamboard. An Arduino reads the phototransistors while the projector runs a calibration routine. [Alex] switched over to a scanning line from [Johnny’s] original binary pattern. The scan isn’t quite as fast as the binary, but it sure looks cool. Once the positions of the sensors are known, it’s just a matter of mapping the entire screen to a smaller piece of real estate. Toss in a few neat transitions, and you’ve got an awesome demo.

If you want to see more projector projects, check out our new projector project list! If I missed your project, don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Altair 8800 Front Panel For An 8080 Emulator

It appears a very important anniversary passed by recently without anyone realizing. The January 1975 issue of Popular Electronics featured the Altair 8800 on the cover, otherwise known as the blinky box that launched a revolution, the machine that made Microsoft a software powerhouse, and the progenitor of the S-100 bus. The 40-year anniversary of the Altair wasn’t forgotten by [dankar], who built a front panel emulator with the help of some much more modern components.

The build unofficially began with an Intel 8080 emulator written for an Arduino. The 8080 is the brains of the Altair, and while emulators are cool, they don’t have the nerd cred of a panel of switches and LEDs. The hardware began as a bunch of perfboard, but [dankar] wired himself into a corner and decided to make a real schematic and PCB in KiCAD.

Despite the banks of LEDs and switches, there really isn’t much to this front panel. Everything is controlled by shift registers, but there is a small amount of SRAM in the form of an SPI-capable 23LC1024. This comes in handy, because [dankar] is running CP/M 2.2 on this front panel emulator from disk images saved on an SD card. Everything you would want from a computer from 1975 is there; an OS, BASIC, and enough I/O to attach some peripherals.

Demoing An 8088

The demoscene usually revolves around the Commodore 64, and when you compare the C64 hardware to other computers of a similar vintage, it’s easy to see why. There’s a complete three-voice synthesizer on a chip, the hardware allows for sprites, a ton of video pages, and there are an astounding sixteen colors, most of which look good. You’re not going to find many demos for the Apple II, because the graphics and sound are terrible. You’re also not going to find many demos for an original IBM PC from 1981, because for thirty years, the graphics and audio have been terrible.

8088 MPH by [Hornet], [CRTC], and [DESire], the winner of the recent 2015 Revision Demo compo just turned conventional wisdom on its head. It ran on a 4.77 MHz 8088 CPU – the same found in the original IBM PC. Graphics were provided via composite output by a particular IBM CGA card, and sound was a PC speaker beeper, beeping sixty times a second. Here’s a capture of the video.

Because of the extreme nature of this demo, it is unable to run on any emulator. While the initial development happened on modern machines with DOSbox, finishing the demo needed to happen on an IBM 5160, equivalent to the 5150, but much easier to find.

Despite the meager hardware and a CPU that reads a single byte in four cycles, effectively making this a 1.19 MHz CPU, the team produced all the usual demoscene visuals. There are moire patterns, bobbing text, rotated and scaled bitmaps, and an astonishing 1024-color mode that’s an amazing abuse of 80×25 text mode with NTSC colorburst turned on.

Below you can find a video of the demo, and another video of the audience reaction at the Revision compo.

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Altair Online

Online Altair 8800 Clone Lets You Play Zork

[Citponys] wanted to share their Altair 8800 clone with the world, and what better way to do so than by hooking it up to the Internet? This hack was pulled off by using a Linux computer which receives a Telnet connection and redirects it to a serial port. This serial port is connected to the Altair clone. In order to connect the serial port to the Internet using TCP, the ser2sock program was used. People can interact with the Altair on the webpage, where there is also a live camera feed showing the Altair’s Blinkenlights.

This is an ongoing project for [Citponys]. Zork 1-3 and Ladder are now available for play. You can interact with other people in the current session; play nice, or it’ll end up a Mad Libs version of ‘Twitch Plays Pokemon’.  Most recently, [Citponys] updated the webpage with a HTML5-embedded terminal emulator. If you want to quit the current session displayed, enter “quit” and you will be redirected to the main menu where you can choose another game. [Citponys] has links to game walkthroughs on the top of the page. We have a soft spot for classic computers and games, especially the Altair. Take a trip down memory lane and play some Zork at the fork where the past meets the present!

[via Reddit]

Hackerspace Intro: Workshop 88

hackerspace-intro-workshop-88

If you find yourself in the West suburbs of Chicago, IL with nothing to do you should head over to Workshop 88. [Andrew Morrison] shot some video at the last public meeting which includes a tour of the facilities. We’ve embedded it after the jump for your convenience.

The clip isn’t so much a tour as it is a POV experience. There’s no narrative and the people at the meeting seem to be oblivious that anyone’s recording video. This makes for a pretty interesting presentation, starting with a little rubbernecking at the projects being shown off at the meeting. From there we pass by a couple of members pulling a wire run through the ceiling of the machine shop. Next we see the electronics lab complete with a Makerbot and a very tidy component storage wall. [Andrew] makes a quick trip through the small music studio before heading back to the main room at the close of the segment.

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Workshop 88 Hosts A Near Space Balloon Contest

hackerspaces_in_space

Launching high-altitude balloons to take pictures of the Earth from space is great fun. Heck, even credit card commercials are now suggesting you cash in your rewards points to organize a space balloon adventure for you and your friends.

Capturing snapshots of the Earth from space is such a good time that Workshop 88, a hackerspace located in the Western suburbs of Chicago, is making a contest out of it. They recently kicked off their second annual “Hackerspaces in Space” competition, a contest to see who can build the best near space balloon for under $250. The contest pits individuals, groups, and hackerspaces against one another, assigning each team a score based on the performance of their high-flying rig.

The winner of the contest will have their design replicated by the crew at Workshop 88, who will then hand out the space balloon kits to randomly selected K-12 schools around the country.

If this sounds interesting, but a contest entry just isn’t in the cards, you can always support the kit distribution by funding their Kickstarter project here.

Phasor A/V PAL Demo Uses ATmega88

[youtube=http://www.youtube.com/watch?v=sCN1bqRG-7o]

Above is a new demo video called Phasor developed by [Lft]. It is run from an AVR ATmega88 and a few passive components, and the result is pretty amazing. [Lft] goes into detail about the tricks he used to get this up and running. The chip is clocked at 17.73447 MHz which is exactly four times the frequency of the PAL color carrier wave which allows him to fake a smooth signal. He also uses a timer trick to get the voltages that he needs. The work done here is beyond hardcore and quite frankly we can’t believe he managed to fit all of this into 8.5 KB of program space with just 1 KB or RAM. We wonder if there’s enough room there to add sound and color to the AVR Tetris project.

[Thanks Sprite_tm]