IMac Reborn With Present-day Parts

September 5, 2012 by Mike Szczys 20 Comments

[Paul] spent his summer bringing an iMac G3 into this decade. There’s plenty of room to work with since he removed the CRT which originally occupied most of the computer’s space. The final project is much more powerful and since he preserved most of the metal mounting parts inside it remains quite strong.

He started by swapping flat screen monitors with his Grandma (who incidentally runs Linux… nice!). She had a 15″ model which would fit nicely in the case so he upgraded her to 17″ and took the old one. With bezel removed it fits perfectly where to old tube had been. Next comes the power supply. It’s mounted on the bracket which held the back of the tube, with a bit of metal removed to clear the air intake. To mount the motherboard he fabricated a bracket at one end where the iMac’s stage drops away. In retrospect he wishes he had rotated the board to make the I/O panel more accessible. The hard drive mounts on the original carriage, and he did some creative gluing to make his replacement DVD drive align with the original optical drive opening. The finished product looks great from the front and sides, with the cables running out the back as the only indication that it’s had some major work done on it.

An STM32 Processor Powers This PC

September 3, 2012 by Mike Szczys 7 Comments

This 32-bit computer is a project [Bogdan Marinescu] built as a contest entry. Sadly he didn’t win, but he did do an excellent job of documenting the build. Having seen several other home built PC projects we’re familiar with the challenges that go into such a thing, and he found some great solutions to each of them.

He started with an STM32F103ZET6 chip. This is an ARM Cortex-M3 processor which brings a lot of power to the playing field. That being said, generating a VGA signal would pretty much zap the usefulness of the chip for other processes so he offloaded that work on a separate Propeller chip. A microSD card serves as storage for the machine, which runs eLua (embedded Lua programming language). There is 1 MB of external RAM and a PS/2 port for keyboard interface. The system is networked thanks to an ENC28J60 Ethernet controller. Don’t miss the video after the break where you can see several demos running on the system.

Continue reading “An STM32 Processor Powers This PC” →

Work Station Includes A Smartcard Lock For USB Ports

August 14, 2012 by Mike Szczys 9 Comments

The USB ports on this work station are locked. In order to use a USB device you’ll need to insert a Smartcard into the reader seen above. The interesting thing here is that this shouldn’t affect your ability to charge a USB device. When you visit the link above make sure to check out the worklog tab as it contains nine pages worth of build information.

The device is conceived of in two parts. There is one board which does the USB switching, and another that takes care of the Smartcard reader. That reader is based on a PIC 16F1939. It readers the Smartcard, verifies the data, then controls the USB switching board via SPI. An ADG714 chip completes the circuit on eight data lines making up the four USB ports. There is also a mechanical relay on the board which can cut USB power. Since this is separate from the data switching, the power could be left on for charging or toggled separately by a card that has permission to charge but not to use the data ports. You can see a demonstration of the system embedded after the break.

Continue reading “Work Station Includes A Smartcard Lock For USB Ports” →

A Custom Monitor Mount Built From Wood

August 12, 2012 by Mike Szczys 14 Comments

[LuckyNumbrKevin] wanted an epic monitor array of his own but didn’t really have the desk real estate to pull it off. His solution was to build a three computer monitor mounting rack with a relatively small footprint.

The design started with some virtual test builds using SketchUp. Once he had it dialed in he began transferring measurements for the base onto some plywood. The rest of the parts are built using dimensional lumber. As the project shaped up he wrapped the edges of the plywood with some trim, and gave the piece a good sanding. After a few passes with a dark stain he was ready to mount the monitors he bought from Newegg.

[Kevin] left a comment in the Reddit thread about the parts cost for his design. Including the monitors, this came in under $300. That does not include the Nvidia graphics card which is capable of driving the trio.

Swapping Out Eee PC BGA Chip For 1.6 GHz Upgrade

August 10, 2012 by Mike Szczys 37 Comments

Personally we find this Ball-Grid Array chip-swap rather horrifying. But if you want to beef up the processor on your 701 Eee PC this is what you’ll need to go through. Not only did [Red Fathom] upgrade to a 1.6 GHz chip, but he managed to get the computer to boot up with the new hardware in place.

BGAs are notoriously hard to solder. This hack pulls it off using just a hot air gun. [Red Fathom] heats the board from the underside until the solder melts and he can pluck off the old chip. He then uses a solder braid and iron to remove extra solder from the footprint. After a little cleanup with a cotton swab and some flux he plops in an Intel Pentium M LV 778. It doesn’t look like he added any solder after the cleaning process. Perhaps he’s relying on the small amount left on the tinned pads of the board?

After the break you can see the soldering process and a video of the new processor booting Xandros.

Continue reading “Swapping Out Eee PC BGA Chip For 1.6 GHz Upgrade” →

Fortifying Veronica’s VGA Output

August 10, 2012 by Mike Szczys 1 Comment

[Quinn Dunki] just moved to a new work space and had to pack up her homebrew computer project — called Veronica — in the process. She just unboxed it again and decided now was a good time to fortify the VGA display hardware. It wasn’t in the greatest of shape, since everything for the initial video tests had been built on a breadboard. The transition to protoboard ended up turning out just swell.

One of the thing’s that we like best about [Quinn’s] hacks is that she documents her failures (or perhaps we should just call them hiccups?) just as much as she does her successes. This is not a small thing. We understand, because our own screw-ups don’t usually get photographed due to our raging need to just make the frakking thing work.

Once she had moved all the components to the new board the circuit was amazingly organized. Since she’s doing high-speed switching with the VGA signals it was important to keep the lines as short and straight as possible, hence the SRAM stack seen above. But when it was first fired up she had a jumble of only-somewhat-organized color stripes. It turns out that she had forgotten to change the color register in the AVR code, the color lines were hooked up in the wrong order, and the switch mode supply was injecting noise into the system. But thanks to her documentation of these issues we’ll know what to do when we find ourselves in a similar situation.

16-bit HCMOS Computer Is A Wire Wrapping Wonderland

July 10, 2012 by Mike Szczys 25 Comments

The D16/M is a 16-bit computer built using HCMOS logic chips. It’s a thing of beauty from every angle thanks to the work [John Doran] put into the hobby project. But he didn’t just take pictures of the build and slap them on a webpage. He took the time to publish a remarkable volume of documents for the computer too!

The processor can execute a total of 73 instructions and offers a 100-pin bus for accessing main memory and peripherals. So far he has documented three different peripheral boards, each of which is pluggable thanks to an edge connector that accepts the board. The expansion boards are for system memory, serial communication port, and a clever four-position SD card interface for persistent storage.

Got a question about the system? He wrote a FAQ. Want to learn from his obvious mastery of wire-wrapping? He wrote a wire wrapping tips guide. Like we said, there’s a mountain of documentation and the links to it all are included in his main project page.

[Thanks Allen]