Converting An IBM PCjr Joystick To USB

February 12, 2013 by Mike Szczys 9 Comments

pcjr-joystick-usb-conversion

Seeing this IBM joystick again really brings back memories. But it can be used on a modern system thanks to this USB conversion project.

This particular model had a connector which is foreign to us. It looks like a boxy USB-A plug, but has an eight-pin sockets which looks like it’s 0.1″ pitch. You could try to make your own male connector using a dual-row pin header, but [Gruso] just went ahead and lopped off the end of the cable. He managed to dig up the pin-out for the device and found that it could be wired up to a gameport — the connector being the only real difference. He gutted a USB gameport adapter, removing the DB15 connector and soldering directly to the board. The boxy old peripheral has just enough room to house that PCB.

If you’re looking for a few more details than this build album provides check out [Gruso’s] comments in the Reddit thread.

$250,000 Hard Drive Teardown

December 7, 2012 by Mike Szczys 64 Comments

worlds-most-expensive-hard-drive-teardown

Have you ever seen hard drive platters this big before? Of course you haven’t, the cost of this unit is way beyond your pay grade. But now that it’s decades old we get a chance to post around inside this beast. [Dave Jones] — who we haven’t seen around these parts in far too long — takes a look inside this $250,000 storage device.

In this episode of the EEVblog [Dave] is tearing down a late 1980’s IBM hard drive. This an IBM 3390. It stores either 1.78GB or 3.78GB. These days we’d never use a mechanical drive for that little storage as flash memory is so much cheaper. But this was cutting edge for servers of the day. And that’s why you’d pay a quarter of a million dollars for the thing.

[Dave] does what he’s known for in the video after the break. He energetically pours over every aspect of the hardware discussing function and design choices as he goes.

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God’s Own Keyboard, Now With Bluetooth

August 9, 2011 by Brian Benchoff 49 Comments

For decades a thunderous roar rose from the bowels of IBM keyboards like the animus of angry and forgotten gods. These keyboards have fallen silent of late, due only to incompatibility with newer hardware. Now, Model Ms have been given a reprieve from landfills or recycling centers because of the work of [wulax] of geekhack and his Model M Bluetooth controller board.

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Who Knew Thinkpad Batteries Require A Jump Start?

August 1, 2011 by Mike Szczys 59 Comments

Lithium battery packs reaching the end of their life usually have a lot of kick left in them. That’s because they’re made up of multiple cells and it only takes the failure of one to bork the entire battery. One of the most interesting examples we’ve heard of this is in the Toyota Prius, but that’s a story for another time. In this case, [Mika] wanted to resurrect the battery from his IBM Thinkpad T40. He identified the offending cell and replaced it, but couldn’t get any juice out of the battery after the repair.

He was measuring 0V on the output, but could measure the cells instead of the control circuitry and was getting over 11V. Clearly, the control circuit wasn’t allowing an output. We completely understand the concept here (think about that really bad press about exploding laptop batteries). It seems there’s a lockout mechanism when the control circuit loses power. [Mika] managed to get past this by shorting voltage into the control circuit, a method he likes in the video after the break to jump starting a car.

We’ve seen similar cell replacement for power tools, like a Dremel or a Makita drill.

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The Origin Of CTRL-ALT-DELETE

April 15, 2011 by Mike Szczys 32 Comments

You may not have ever thought about it, but the far-too-often-used keyboard combination of Control + Alt + Delete had to have been brought into existence by some random coder at some point in technological history. But wait, it wasn’t just a random coder. The keystroke combo is attributed to [David Bradley]. He was one of the original designers of the IBM Personal Computer. You can even hear his own recount of the story in the video after the break.

He came up with the idea after growing weary of waiting for the Power-On Self Test (POST) routine to finish during each reboot of his software testing regiment. We remember the old days of slow hardware and can understand his frustration at the lost time. He decided to throw in a shortcut that allowed the software to reboot without power cycling the hardware. The original implementation used CTRL-ALT-ESC, but was later changed so that one frustrated keyboard mash couldn’t accidentally reboot the system.

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Making Punch Card Programming A Snap

January 6, 2011 by Mike Szczys 47 Comments

About thirty years ago [H. P. Friedrichs] pulled off a hack that greatly improved the process of programming with punch cards. At the time, his school had just two IBM 029 keypunch machines. One of them is shown in the upper right and it uses a keyboard to choose which parts of each card should be punched out. This was time-consuming, and one misplaced keystroke could ruin the card that you were working on. Since you had to sit at the machine and type in your source code these machines were almost always in use.

But wait, the school acquired a dozen of the TRS-80 computers seen in the lower left. They were meant to be used when teaching BASIC, but [HPF] hatched a plan to put them to task for punch card generation. He built his own interface hardware that connected to the expansion port of the new hardware. Using his custom interface a student could create a virtual card deck that could be rearranged and revised to correct mistakes in the source code. The hardware then allows the virtual deck to be dumped in to the punching machine. This broke the bottleneck caused by students sitting at the punch card terminal.

We think that [HPF] sent in this project after seeing the antiquated hardware from that 1970’s calculator. These hacks of yore are a blast to revisit so don’t be afraid to tip us off if you know of a juicy one.

Gaming On An IBM XT Using An NES Controller

December 24, 2010 by Mike Szczys 27 Comments

[Frode] felt that using the keyboard for gaming on his old IBM XT computer was simply too noisy. He came up with a much quieter way to game by building an XT adapter for an original NES controller. If you haven’t explored the communication protocol used by the NES peripherals this is a great way to learn. Inside you’ll find a CMOS shift register that captures button states when it receives a latch signal. With that in mind [Frode] came up with a circuit to gather the bits from the controller, and generate input commands using the XT keyboard protocol without using a microcontroller. All of this is explained in the demo after the break.

Most of the NES controller hacks we see permanently alter the hardware. It’s nice to see one used without cracking it open.

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