66% or better

J1: a small, fast, CPU core for FPGA

[James Bowman] of the Willow Garage published a paper on his J1 CPU core for field-programmable gate arrays. This was originally developed and used for the Ethernet cameras on the PR2 (you know, that incredibly expensive beer delivery system?) robot. It uses a 16-bit von Neumann architecture and lacks several processor features you’d expect a CPU to have such as interrupts, multiply and divide, a condition register, and a carry flag. None-the-less, its compact at just 200 lines of Verilog and it can run at 80 MHz. [James] compares the J1 to three different FPGA CPU Cores commonly used and discusses how the system is built in his 4-page paper that has the details you’re interested in but won’t take all day to dig through.

Electromechanical computer built from relays

This is Zusie, a computer built out of electromechanical relays. [Fredrik Andersson] picked up a lot of about 100 telephone exchange circuit boards, each with about 16 relays on them. After getting to know a heat gun really well he ended up with 1500 working relays with which to play. The machine runs slowly, it iss noisy, but it definitely works. After the break you can see it running and assembly code program that he wrote.

The instruction set is based on boards running microcode. These store the operational commands for each instruction the processor has available to it and they run in parallel with the rest of the operations.

We’re always surprised to see that these home-built processors work. Mostly because of the complexity involved in assembling them. How hard is it to find a shorting connection or a malfunctioning relay? Those problems aren’t limited to this application either, what do you do if a transistor-logic CPU has a malfunctioning chip?

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iPhone 4 teardown

iFixit traveled all the way to Japan to bring you this iPhone 4 teardown, only to be shipped the device unexpectedly two days early!

We were surprised that the A4 processor (its naked body displayed for the world this past April) contained within the iPhone 4 had 512MB of ram, compared to the 256MB of the iPad. Other features include the 1420mAh battery (201mAh more than the 3Gs), 5MP rear camera and front VGA camera, and the use of micro-sim.

Frankly, we don’t see ourselves getting the device immediately, but how excited are you for the iPhone 4?

DUO 128 Elite, 4 bit CPU

We’re not sure how we missed [Jack Eisenmann's] 4 bit TTL CPU when we were tipped off the first time, but we’re glad it was sent in again for us to feature it.

41 different ICs (mostly TTL) come together to comprise the DUO 128 Elite. While the architecture is a little different than what we’ve seen before, using “nyckles”, the DUO 128 Elite still works perfectly. Catch a video of some example programs, including pong, after the divide.

[Thanks Marc G-C]

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Cool yourself with a CPU cooler and beer fridge

We have arrived once more at the time of year when penniless (or bored) hackers try to figure out how to keep the place cool without buying an air conditioner. [Paul Stacey] sent us his solution of pairing up a CPU cooler kit with a beer fridge. The CPU heat sink is cut out of a liquid cooling kit and discarded. In its place a loop of plastic tubing enters the freezer of the beer fridge where it exchanges salt water from a reservoir. The cold liquid circulates through the radiator of the fan kit and gives up it’s cool goodness through the fan unit seen above. This method puts a cold-air fan right in front of you with a digital temp and fan speed readout on the LCD.

Our biggest concern here is that this might heat up the beer in the fridge. Still, it’s more automatic than using a homebrew swamp cooler. Then again, we’ve always had a soft spot in our hearts for our favorite gravity fed cooling method. Anyway, check out [Paul's] build methods after the break where he makes it look quick and easy.

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CPU as a heat sink

We’ve noticed that wireless routers pump out a bunch of heat. [Jernej Kranjec] wanted to make sure that he didn’t fry it once he started adding more load to his router using OpenWRT. What he came up with is the idea of using an old CPU as a passive heat sink. He applied a bit of thermal paste to the center and some super glue to the corners. You can see the finished product is an old AMD chip adhered “dead bug” style to the stock processor. We’d bet it’s not very efficient compared to an aluminum or copper heat sink, but it normally would have no help in shedding those extra degrees.

Hackaday links: March 28, 2010

Cardboard record player

[Yen] tipped us off about this cardboard record player. It’s a marketing tool that you receive in the mail. Inside the cardboard packaging is a record and the packaging itself can be folded into a player.

Hackable handheld

The NanoNote is a tiny handheld housing a lot of power for a small price. It ships running openWRT and sports a full keyboard, 336MHz processor, 32 MB ram, and 2 GB of flash memory. Not bad for $99. [Thanks Drone via Linux Devices]

Virtual page flipping physical interface

Love reading ebooks but miss flipping through the pages? [Marcin Szewczyk] developed this interface that lets you flip a couple of sheets of plastic to turn and fan through pages on the screen.

Augmented reality tat

Not interested in supporting an ink artist or just can’t decide on the design? Perhaps you should get an augmented reality marker tattooed on your arm and have the art digitally added for those who have already made the switch away from using their analog-only eyes. [Thanks DETN8R via Asylum]

Cooking with a CPU

[Bo3bo3] is practicing the art of cooking with processors but he’s bumped things up a notch. Instead of cooking inside a computer case, he removed the processor from the board and made it USB powered. [Thanks Waseem]