REXHardware Hacks

risky business

WARNING
If you can't handle the thought of tampering with your REX, or if you are a klutz with a soldering iron, or if you don't even know what a soldering iron is, then do yourself a favor and just go back to the index!

hacker

hâk'er n. 1. One who modifies a device to perform a function that was not intended. 2. A person who is very proficient at reprogramming a computer. 3. inaprop. One who compromises the security of computer systems (see cracker).

This page is for the true hackers out there who aren't satisfied with the current state of their REX 6000. "If it ain't broke, it just ain't good enough!" This page is to encourage the exchange of ideas about extending and improving the REX 6000 hardware. If you have another idea to add to this page, please drop me a line. I will post any results on this page, complete or not. If we collaborate on these projects, we can probably make some progress.

disclaimer

These ideas are risky and will void your warrantee, and therefore are not for the squeamish. If you happen to pull one of these hardware hacks off, I would like to hear about it. Of course, if your mess up, be accountable for your own mistakes and don't go blaming me. If you decide to take one of these projects on, you do so at your own risk. I cannot take any responsibility for any damage that you may do. We can learn from the mistakes, so let me know about those, too.

Everything I know about these subjects is here, so don't e-mail me asking for more info. I am doing research myself, and will post any information I find here. If you have any sort of success or any further information on these projects, please let me know so I can post your results on this page.

power possibilities

Here are some unproven possibilities for improving the power capabilities of the REX. They require further research and testing, and are not recommended for the unexperienced.

  • Build a PCMCIA jack and a 4xAAA battery holder into a small enclosure to create a very portable, powered case. Rechargable NiMH batteries would provide virtually unlimited power.
  • Install rechargable CR2016 batteries in the REX. Modify the REX power-management circuitry to charge these batteries when the REX is plugged into the cradle. This could be as simple as substituting a resistor for a diode.

results

Serial Cradle Conversion by David

Powered Case Prototype by Mark

To use a powered case, you will need the "Dock Patch" from Chris Harris.

rex text printer

Given these points:

  • Most printers will accept straight text, and print it out in a default font.
  • Many portable printers have a serial interface.

You could probably do this:

  • Find the serial output on the REX's PCMCIA port, and build an adapter that plugs into the REX on one end and a serial printer on the other.
  • Write an add-in application that will dump a file through this interface, followed by a formfeed character to eject the page.

You could probably find a tiny, battery-powered serial printer and plug your REX into it with this adapter. Run the "Print" add-in, choose a file (usually a Memo), and print it on the printer. It's probably possible for a Print add-in to print any data within the REX. Nifty!

results

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modem

From Jabberwock:

My idea is a "black box" with two PCMCIA slots: To one we connect a modem, to another we connect the REX. Then with a REX addon we connect to an ISP and check mail, etc. Is this possible technically? No idea. It may be worth considering, as it would be the very portable and very convenient.

results

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input devices

REX Keyboard

Another possibility is to create an adapter to plug keyboards, mice, tablets, etc. into the REX 6000 as an alternative input device. This would require basic changes to the firmware itself to support the adapter and devices. At this point, the firmware remains a locked box.

One idea [thanks Nuri] would be to adapt a PDA keyboard to fit into the REX wallet case. This would require first finding a keyboard the size of a credit card, then modifying the hardware to connect to a PCMCIA plug, fitting the plug and keyboard assembly into the case, and finally modifying the REX firmware to recognize the keyboard. Not easy.

results

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controller

How about using the REX as a controller for another device? The size, programmability, and touch-screen are perfect for this. The first idea that comes to mind is creating an interface circuit with a PCMCIA plug for a robot (similar to Lego Mindstorms). Plug the REX into the robot, and it sends movements commands through the interface. Use the REX as its brain, and provide buttons on the REX screen to tell the robot what to do!

Bertus had this idea:

"Some time ago I was contemplating turning my Rex into a remote control for TV and stereo. I imagined a small attachement to the Rex with a led and some electronics to drive it. I found a document on how to build such a device, which can be driven through a RS-232 port. The RS-232 bitstreams are synchronised to provide a certain wave pattern recognised by the receiver of TV's and stereos, etc. A startbit (0) is sent, then a databit, then a stopbit (1). The circuitry would read the output into a latch only after the startbit, so that the IR on/off can be controlled using the databits only.

"The circuit needs more than 4.5V as far as I can tell, so it would need an external battery, which would make it quite a lot bigger. Then some software would have to be written to drive the serial port of the Rex, which should be possible; after all, it's communicating with the PC through RS-232 as well."

Here is the document from groups.google.com, entitled "Plans for serial-driven IR remote controller (finally!)."

results

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contact

More ideas? Additional Information? Success, either partial or complete? Failures, caveats, or dangers? Let Me Know

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