Laptop Motherboard Reborn As A Low-wattage Server

November 2, 2012 by Mike Szczys 52 Comments

[Darknezz] sent us a set of photos and some details about his damaged laptop motherboard turned into a server. A client brought him a Dell 1525 on which nothing was showing up on the LCD screen. The HDMI and VGA still worked, and he traced the problem to no signal coming out of the motherboard. He swapped the board out to get the laptop working again, but he client said he could keep the damaged one.

It has a dual-core CPU which meets his needs and since it’s meant to run off of a battery it’s as energy-efficient as possible. [Darknezz] dug through his parts bin and found a PSU that could supply the needed 19.5V at 3.5A. The connector didn’t match but it didn’t take him too long to patch into it using a spare Molex connector. He also needed a power button and ended up soldering a momentary push switch to a couple of pads which he traced out form the original connector. The only thing he actually ended up purchasing were the memory modules. Check out the photos he took of the alterations in the gallery after the break.

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How Computers Work, Starting With Transistor Gates

November 1, 2012 by Mike Szczys 11 Comments

[Andrew Gibiansky] has just started a tutorial series called Computing with Transistors. It’s purpose is to pull back the many veiled layers between high level languages and the controlling of electrons. And fittingly this first post starts off by explaining voltage source, load, and current. Don’t be thrown by its simplicity though. [Andrew] quickly moves on to talk about switching transistors and how they are used to build gates like the OR NOR gate seen above.

If this is the least bit interesting you should also look back at the post about Nand 2 Tetris. It’s an online course that works its way through The Elements of Computing Systems text book. We’ve been following that journey ourselves, having made it through the hardware build in about a week. The assembler took about the same amount of time, and right now we’re in debugging hell trying to get the last function call and return parts of the VM translator to work right. We’ve used most of the skills needed in this journey before, but never all in one project. It really has shed a lot of light on the gaps in our knowledge, and we’re having a lot of fun at the same time!

[via Reddit]

Waterfall Swing Set

October 14, 2012 by Jeremy Cook 21 Comments

[Doped Boron] wrote in to tell us about this waterfall swing by [Dash 7]. Naturally, we had no idea what a “waterfall swing” was. Shown at the World Maker Faire in 2011, the device is a swing set capable of accommodating one or two people using it at a time. What makes it interesting, is that water comes out of the top support bar, forming a wall of water for the riders to pass through. This wall is then broken when the swing user flies through it making for a dry experience.

According to the article, 273 solenoid valves are used to control the wall of water. These solenoids are controlled by a computer with sensors that detect where the riders are in the air and what speed they are going. As with most good hacks, it may not serve a “grown-up” purpose, but a set would definitely make a trip to the park more interesting!

Be sure to check out the videos after the break. The first shows the swing in its traditional role, but the second may be even more interesting, showing full control of the swing solenoids for water writing! Continue reading “Waterfall Swing Set” →

Programming Tetris By First Building A Logic Gate, Then A Computer, Then…

October 11, 2012 by Mike Szczys 25 Comments

Hone your fundamental understanding of computer systems by completing this online course called NAND to Tetris. The idea is to develop each fundamental unit that goes into making computer programs a reality. This starts with logic gates, which are put together into modules that eventually become a functioning computer. From there you need an operating system, a compiler, and eventually you’ll be playing a game of Tetris which you programmed yourself.

It’s certainly not an easy journey, but if you have a computer at your disposal you should be able to make it all the way through the course. There’s a software suite which includes a hardware simulator so that the computer you’re building can be assembled using HDL instead physical components.

The concept is discussed in this TED talk given by [Shimon Schocken]. It is also embedded after the break and in addition to the NAND to Tetris project he shows off some self learning software on the iPad. To us it seems very much like the learning software [Neal Stephenson] envisions in the Young Lady’s Illustrated Primer from his Diamond Age novel.

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Try Out Your Assembly And BASIC Skills With A ZX Spectrum Project

October 4, 2012 by Mike Szczys 15 Comments

It can be really hard to warm up to coding in Assembly. But this tutorial looks to make it understandable and (almost) easy. It focuses on programming a game for the ZX Spectrum. But you won’t need the hardware on hand as you can just use the ZX Spin emulator as you work your way through the code.

Ostensibly this is a 30-minute tutorial but that’s a gross underestimate. We finished a cursory read of the tutorial and the building blocks are certainly clear and easy to understand. But we like to make sure we understand every line of code and plan to spread that out over the coming weekend.

The first chapter eases us into machine code by combining it with a bit of BASIC. You’ll see how to manipulate the ZX Spectrum memory and then pluck that value back out into the BASIC program. But once chapter 2 hits it’s pretty much all assembly from there on out. The nice thing is that as you go along you learn how the hardware works and there are quite a few references to pages in the manual so you can do some extra learning along the way.

[Thanks Mathilda]

Tri-mounted Monitors Using Strut Channeling (no Welding)

September 27, 2012 by Mike Szczys 15 Comments

[Optec] want his own triple monitor setup built to his specifications. It turns out to have been a pretty easy project thanks to his mastery of stock materials. The image above is just a bit dim, but if you look closely you can see the strut channel which makes up the monitor frame.

When it comes to this type of metal strut material there’s a lot to choose from. [Optec] went with the half-slot format which provides a little bit of left and right wiggle room. This is important to get the edges of those monitors to butt up to one another. After making a pair of relief cuts he bent the channel in two places, using 45 degree brackets as reinforcement. The monitor mounts are made of MDF with countersunk holes to hide the bolt heads which connect it to the channel.

He figures the total cost of the mount was around $40. Seeing how easy it was makes us think we may never buy a commercial TV mounting bracket again. Of course if you’re more into woodworking there’s a tri-monitor project for you too.

[via reddit]