Quadruped Military Vehicles From Back In The Day

May 28, 2011 by Mike Nathan 14 Comments

While Boston Dynamics’ Big Dog is pretty impressive, check out this video of the US Army’s first attempt at a quadruped vehicle. Created in the early 1960s with the help of GE, this Army experiment was the first successful attempt of replicating a four-legged animal with a mechanical machine.

This “Walking Truck” was driven by a single operator who moved each of the vehicle’s legs using force-feedback hydraulic levers. Choreographing the machine’s movement was quite complicated, and during testing the Army found that the operator needed a mental break after only 15 minutes of use. As you can see in the video, the vehicle flexes some serious muscle. It kicks a Jeep out of its way with little effort, but it is still able to gently step on a light bulb without breaking it, due to the level of tactile feedback received by the operator.

If it weren’t for government budget cuts, we could be living out [George Lucas’] dream of AT-AT based combat right this minute!

[via Gizmodo]

Minimalistic 555 Adding Machine

May 27, 2011 by Nick Schulze 6 Comments

How many 555 timers does it take to add up two 10 digit numbers? [Alan’s] 555 Adding Machine does it with 102 of them, he designed the machine as an extreme entry to the 555 contest and the original plan was to make it even more complicated. This machine uses the 555’s to implement a nine decade accumulator and multiplexer, all inputs are managed by an old school dial from a rotary phone which apparently provide nicely timed outputs. Addition and subtraction are achieved using 9s compliment arithmetic which he discusses in the video after the break, for anyone who wants to brush up on 9s compliment or 555 theory.

Alan’s website has some nice pictures (We’re particularly impressed by all that minimalistic soldering) including schematics, and a very nice 33 minute video in which he discusses in detail how the machine works and even offers some history on the Pascaline, which is mechanical calculator that works on similar principles.

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Adding Persistent Memory And Ethernet To Vintage Arcade Machines

May 27, 2011 by Mike Nathan 13 Comments

z80_bus_tapper

If you are a frequent reader, you are undoubtedly familiar with hacker [Sprite_tm]. He has been working with fellow members of the TkkrLab hackerspace to get things ready for their official grand opening on May 28th, and wrote in to share a project he recently completed to kick things off.

As part of their preparations, they have been stocking the joint with all sorts of hacker-friendly goodies including plenty of tools and Club Mate, as well as a vintage ‘1943’ arcade cabinet. The game is a group favorite, though every time the power is turned off, it loses all of the hard-earned high scores. [Sprite_tm] knew he could improve on the current paper-based score register, so he pulled the machine open to see what could be done.

He used an AVR to tap into the machine’s Z80 logic board, allowing him to read and write to the entirety of the game’s RAM whenever he pleased. This enabled him to keep tabs on the high scores, restoring them to memory whenever the machine is powered back on. The addition of the AVR also allowed him to add a TCP/IP interface, which is used to send high scores to Twitter whenever someone beats the previous record.

His modular bus tap can be used in all sorts of Z80-based hardware, so if you have some vintage equipment laying around, be sure to swing by his site for a more detailed look at the build process.

Hacked Phone Runs Zork, Gets Lamp

May 25, 2011 by Brian Benchoff 14 Comments

A few months ago, [Ulysses] had a project in mind that would run Zork on a TDD. Although it was a bit of a struggle getting the project ready in time for the Bay Area Maker’s Faire, the accompanying build blog tells us it was more than worth the effort.

After hooking up the guts of the phone to an Arduino Pro, A modem was modified so the acoustically coupled TDD could be interfaced. Although the TDD display is only one line, [Ulysses] is transmitting the text at only 45.5 baud, So even the slowest reader could keep up with the story. For running the actual code, initial attempts at using an Arduino Pro, and then Arduino Mega proved unsuccessful because of the limitations of sram in these AVRs. After discarding the idea of running Zork on an Arduino, the project was finished with a single board FitPC computer mounted inside the phone.

The code of the project runs Zork on a port of the Infocom Z-code Interpreter Program, or ZIP. A lot of interactive text adventures were put out in the Z-code format, so we’re guessing it would be trivial to have this project run Leather Goddesses of Phobos, or the amazing Hitchhiker’s Guide to the Galaxy. It’s a very nice project, and we could easily see ourselves sitting down with this project, a two liter bottle of Shasta, and an all-Rush mix tape on a Saturday night.

Shoehorning RS-232 Into A Minitel Terminal

May 22, 2011 by Brian Benchoff 30 Comments

In the early 80s, millions of terminals were handed out to French telephone subscribers. Nearly 9 million of these Minitel dumb terminals were in use at one time, and with that degree of ubiquity, we’re surprised we haven’t heard of them before. These boxes were usually connected to the outside world through their internal 1200bps modem, but [O. Blt] came up with this build (Google Translate link) so he could connect to a local machine with an RS-232 port.

After digging up the pinout for the Minitel’s DIN-8 port, [O. Blt] designed a little board around a MAX232 chip scavenged from an old motherboard. Of course there was a need to get the terminal to do something, so [O. Blt] used the Minitel as a display and remote control for Winamp. The project was successful, but not very useful – at 1200 bps, the refresh is very, very slow.

American readers may remember connecting to the Minitel network with their Apple ][s and C64s with CommunityLink, but this service was driven out of the market by the giants of pre-web dial-up, Prodigy and Compuserve. In any case, after seeing the AZERTY and alphabetic keyboard layouts of these old boxes gives us a feeling of nostalgia for a time before everything dealing with computers was standardized.

BAMF2011: Keyboards Built From Scratch

May 21, 2011 by Phil Burgess 35 Comments

As the most direct interface between computer and programmer, keyboards can be a deeply personal, sometimes almost religious thing. Some find solace in their vintage IBM Model M, or luxurious leather keyboard, but maker [Carol Chen] took things into her own hands, quite literally. [Carol]’s Maker Faire exhibit has a half dozen specimens of interesting commercial tactile and ergonomic options…but [Chen]’s personal keyboard, where she commits to her work as a full-time coder, has been made to her own exacting specifications.

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Arduino Magnetic Core Memory Shield

May 11, 2011 by Mike Nathan 14 Comments

mag_core_memory

Magnetic core memory turns 60 years old today, and as a tribute [Ben North and Oliver Nash] have created a 32-bit magnetic core memory board for the Arduino.

Magnetic core memory was used from the 1950s through the 1970s, and provided a non-volatile means for storing data, as each magnetic core retained its orientation, even when the power was cut. While it sounds a lot like a modern hard drive, these devices were used in the same fashion as RAM is utilized today.

While the pair used surplus ferrite cores manufactured just before magnetic memory stopped being produced, they did allow themselves to use some modern components. Items such as transistors and logic gates were not available to the first magnetic core memory manufacturers, but the use of these items helped them complete the project in a reasonable amount of time.

Their final result is a magnetic memory board which can be used by any USB-enabled device and is reliable enough to withstand billions of read/write transactions.