Tiny External System Monitor Makes It Easy To Keep Tabs On Your PC

August 2, 2011 by Mike Nathan 13 Comments

tiny_pc_resource_monitor

Instructables user [Jan] likes to keep close tabs on his computer’s memory usage, but wanted something more interesting to look at than the standard resource manager. He preferred to have an external display available that would show his computer’s status with a quick glance, and thus this system monitor was born.

His status panel contains a trio of constantly updated LED bars that show his computer’s CPU usage, available physical memory, and virtual memory consumption. With a small footprint being a priority, [Jan] kept the indicator’s size down by using SMD components and by including an on-board UART to USB converter to go along with his ATTiny microcontroller.

He uses a Python script to gather usage information from his computer, feeding it to his display over USB. The system works pretty well as you can see in the video below, though the virtual memory indicator doesn’t seem to get a ton of action – perhaps it could be used to indicate hard drive activity instead.

If you are looking to build something similar, [Jan] has made all of his code and schematics available for anyone’s use.

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Commodore 64 USB Controller Adapter For Your PC

July 31, 2011 by Mike Nathan 11 Comments

commodore_64_controller_usb_interface

[Frank], like many people, has a soft spot in his heart for the Commodore 64. He prefers to play his C64 games on his computer nowadays, but likes using his old school Competition Pro rather than some modern controller with remapped buttons. The only problem with using the controller is that his new computer doesn’t have any ports that accommodate its 9-pin D-sub connector.

The VICE emulator maps keyboard inputs to controller actions, so he decided to build himself a D-sub to USB adapter that implements a virtual USB keyboard. He wrote a firmware package for the Freescale MC9S08JS16L microcontroller that allows him to send keypresses to his emulator whenever he performs an action with his Competition Pro joystick.

The circuit looks easier to duplicate than some other C64 interfaces we have seen before, and as you can see in the video below, it works quite well. We imagine that this setup can be used to connect all sorts of old input devices to modern PCs with little to no tweaking.

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Building A Computer Around A TTL CPU

July 18, 2011 by Mike Szczys 26 Comments

[Bill’s] worked on his homebrew computer for almost a decade. He didn’t start with a Z80 processor like a lot of the projects we’ve seen, but instead build the CPU itself from 74-series TTL chips and a ridiculous amount of wire wrapping to connect it all.

The video after the break shows off the functionality. We love the front panel, which is packed with information but manages to remain organized and offers many convenient features. Our favorite is the ability to pause execution and scroll through the registers by spinning the dial. The clock signal has a variable speed which is selected by an internal DIP switch package that can be changed during a pause. It runs MINIX and has a library of programs, but perhaps most surprising is its ability to serve webpages.

Lately we’ve been interested in drilling down through program language abstractions to understand what is going on inside the silicon. This has given us new respect for those building processors from scratch. Think of it this way, if you actually need to build each instruction out of gates, you’ll be able to understand how those instructions work at the most fundamental level.

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Don’t Buy An IPAD, Make One!

July 17, 2011 by Nick Schulze 37 Comments

When [Liu] decided he wanted one of the new iPads, rather than fork out the cash he decided to build his own tablet Mac. His creation functions just as you would expect any tablet PC with some nice extra features such as running on Windows XP for any of you Microsoft lovers. [Lui’s] tablet apparently only cost him about $300USD, about half the price of the real thing. The two part video shows the entire construction in fast forward including a demonstration of the final working product. It looks like the tablet is built using spare tablet/laptop components and the case is constructed from sheet aluminum before being painted and labelled with apple stickers. The final product is a bit thicker than the real thing but looks great in the laptop style case [Lui] has whipped up. Kudos to the guy for saving a few bucks and making something great in the process, the video after the break is definitely worth a watch. This isn’t the first time we’ve seen this kind of thing, actually we’ve seen a few.

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Smile, Your Face Is On The Internet

July 7, 2011 by Mike Szczys 98 Comments

[Kyle McDonald] is up to a bit of no-good with a little piece of software he wrote. He’s been installing it on public computers all over New York City. It uses the webcam found in pretty much every new computer out there to detect when a face is in frame, then takes a picture and uploads it to the Internet.

We’ve embedded a video after the break that describes the process. From [Kyle’s] comments about the video it seems that he asked a security guard at the Apple store if it was okay to take pictures and he encouraged it. We guess it could be worse, if this were a key logger you’d be sorry for checking your email (or, god forbid, banking) on a public machine. Instead of being malicious, [Kyle] took a string of the images, adjusted them so that the faces were all aligned and the same size, and then rolled them into the latter half of his video.

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Compaq Portable III Rises Again For A Noble Cause

June 9, 2011 by Gerrit Coetzee 36 Comments

[Autuin] found a Compaq Portable III destined for the scrap bin at Free Geek Vancouver. Upon seeing it he realized that it still had some fight left in it — perfect to go up against the tyranny of hipsters and their shiny Macbook Pros at his local coffee shop.

Unfortunately, being a 286, the computer couldn’t do much. He could take the usual route; which is to remove all the internals, and use the vast amount of space to fit a more modern computer inside. However, he decided to go a different path and save the internals, leaving it in original working order. The computer didn’t have enough power to browse the web, but it had just enough room to fit a small single-board computer inside, to which he could connect through serial. He hasn’t taken it down to the coffee shop yet, but we’re hoping for a few horrified hipsters and a full mission report when he does.

Thanks to [Alec Smecher] for the tip.

Fixing POST Errors With A Single Key

May 29, 2011 by Mike Nathan 60 Comments

one_key_keyboard

Instructables user [Mike Craghead] was in the middle of building a very compact public computer kiosk when he ran into a problem with the processor fan. It was too big for the enclosure and had to be swapped out with a fan that did not allow the motherboard to monitor its rotational speed.

Motherboards don’t like this situation very much, and each time the computer was started, it would hang at the BIOS screen waiting for someone to press the F1 key to continue. Knowing that everything was just fine, and that there were no BIOS options which would allow him to ignore the error, he crafted a simple solution to the problem.

Since the computer just needed someone to press the F1 key, he figured he could rig up a small dongle that would always hold down the key for him. After verifying that the OS would ignore the stuck key, he tore apart a keyboard and traced the circuit matrix to identify which pins he had to short in order to represent the F1 key press.

Satisfied with his handiwork, he plugged the board into his computer and found that everything worked just fine. Sure it might not be the most elegant solution to the problem, but it gets the job done at a cost of zero dollars – you can’t beat that!