Update: 6809 Computing

December 15, 2010 by Chris Nelson 26 Comments

[Matt Sarnoff] is designing his own 8-bit computer from scratch. This means not only designing the hardware but also writing his own kernel and custom libraries. Since we last saw this 8-bit machine hes added both video and sound output which has allowed him to start developing some software for his computer (see it play Conways game of life after the break).

Sticking with the retro theme of his computer he uses a TMS9918 chip to output the video and a YM2149 for audio. The YM2149 was the audio chip used in the Atari ST allowing him to play songs generated for that system with a little bit of hacking to account for the fact that the Atari ST ran at 8MHz where his Motorola 6809 only runs at 2MHz.

Via [Retro Thing]

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Lego Machine Predicts Future Eclipses

December 9, 2010 by Mike Szczys 23 Comments

Hidden behind the white face plates of this machine are racks of gears that make up a replica of one of the oldest known mechanical computers. This is a working model of the Antikythera mechanism made from Lego pieces. In the video, which you absolutely can’t miss after the break, The machine is disassembled into its various components. Each mechanical unit takes advantage of gear ratio combinations to perform numerous levels of mathematical functions in order to display the date and time that future celestial events will occur.

The background information on the original device reads like the script for a sequel to The Goonies. Believed to date back to 100-150 BC, the ~~stone~~ bronze mechanism was recovered from a shipwreck around the turn of the twentieth century. The use of x-ray analysis helped to unlock the functions and confirm the theories of its operation.

Part of what makes this so interesting is the historical connection. But the production quality of the video (which to be fair, seems to be an advertisement) really brings home how complicated this process is. Now it’s time for us to watch the video a few more times, sketching out the gearing to see that this works as they say it does.

Want more of the Antikythera mechanism? Check out the model built by [Tatyana van Vark].

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ATX Psu Turned Into An Adjustable Voltage Bench Supply

December 9, 2010 by Mike Szczys 37 Comments

Here’s a fancy way to convert an ATX powers supply into a bench supply. [TG] didn’t just cut off the motherboard connector and add banana plugs, but improved the functionality. Right off the bat you’ll notice that he’s added a control panel. There is an Ammeter and Ohmmeter to let you know what the unit is putting out. He added an MIC29152WT adjustable voltage regulator so that he’s not limited to the fixed voltages of the psu. As a final touch he added an external voltage probe which can be used with the flick of a switch. It’s no replacement for a proper bench supply, especially since it doesn’t have adjustable current limiting, but it’s a nice improvement upon previous psu hacks.

Debug Mode Lurking Inside AMD Chips

November 13, 2010 by Mike Szczys 50 Comments

Looks like some hardware enthusiasts have worked out a method to enable debug mode within AMD processors. The original site isn’t loading for us, but the text has been mirrored in this comment. Getting the chip into debug mode requires access passwords on four control registers. We’ve read through the writeup and it means very little to us but we didn’t pull out a datasheet to help make sense of the registers being manipulated. It shouldn’t be hard to find an old AMD system to try this out on. We’d love to hear about anything you do with this debug system.

[via Slashdot]

Swiveling Arms Replace Laptop LCD Hinges

November 8, 2010 by Mike Szczys 24 Comments

This swivel arm LCD screen is [Ben Heck’s] latest hack. It replaces the hinges that normally only allow one point of rotation on the screen. You can still use the laptop like normal, but when space is at a premium a second adjustment, both in rotation and linear position, has been added using the slots and screw knobs seen above. Ostensibly this is to use on an airplane, where there may not be enough space to fully open your laptop. We’ll let you decide if it’s wise to try to get your own hacks past airport security. Historically, the TSA hasn’t been impressed with hardware hackers. We like how this came out and could see ourselves using these techniques to make a convertible tablet notebook by reworking the cable routing.

We’ve embedded [Ben’s] quick demo of the finished product after the break. If you want to see the whole build process it is the subject of Episode 5 of the Ben Heck Show.

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90 TB Drive Array For Home Storage Needs

October 21, 2010 by Mike Szczys 53 Comments

Why store it in the cloud when you could have a 90 Terabyte hard drive (translated) array in your house? The drives are mostly Western Digital Caviar Green EARS 2TB models which are known for energy efficiency and quiet operation. It’s a little unclear as to whether this is using one or two motherboards, but the drives are connected using PCI RAID5 and RAID5+0 controller cards. There’s a total of 40 cooling fans built into the case, half on the bottom and the rest on the top. They move air up through the case, with plans to add a dust filter in the future. Heck, with that type of air movement you could throw on a standard furnace filter. Apparently it is quiet enough to talk in “almost a whisper” while next to the plywood monolith. But we’re a bit skeptical of that claim.

It’s not quite as fancy looking as the 67 TB storage from last year… but it does look pretty easy to build at home.

[Thanks Henrique via EnglishRussia]

Creepy HDD Activity Lights Just In Time For Halloween

October 11, 2010 by Caleb Kraft 23 Comments

We almost skimmed right past this spooky HDD activity light thinking it was just another set of LEDs wired to the motherboard. However, they explained right off that they didn’t want just another blinking light on their case. They wanted it to change its intensity smoothly based on hard drive activity. While there are a million ways this could have been over engineered, we think they did a pretty good job of simplifying the circuit. The bill of materials is pretty much just a handful of resistors, LEDs, an opto isolator, and a capacitor. The effect, is quite nice and can be seen in the video after the break.

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