Pocket Connectivity for Frugal Hackers

by Mr. Curious

When the Sharp Zaurus ZR-3500X first hit the market, its list price was a hefty $399.  Today, about a year later, it is possible to find a refurbished model for a mere $99.  This price drop, which exceeds even Moore's Law of computing depreciation, is due to two things: first, the engineering department at Sharp designed the casing in a chintzy way and the hinge where the machine opens tends to break shortly after opening and closing it a few times (but is quite fixable with superglue), and second, the market is being flooded with assorted handhelds, most of which run the market-heralded Windoze CE, the hand-held OS of choice for your button-down suit types.

The Zaurus, on the other hand, has an OS all its own - one which is neither great nor horrible, but somewhere in-between.  But for $99, hackers would be challenged to find a better mobile computing and hacking tool.

The lowdown on the machine, in 50 words or less: size of a checkbook, 2 MB RAM (1 MB of that is FLASH, for backup), on-screen drawing, calendar, scheduler, phone book, data bank, outliner, spreadsheet, fax modem, backlit 320x200 monochrome LCD).

The unit's most powerful feature, in my opinion, is the internal 9600/14400 fax modem.  Documents can be typed with the built-in, relatively powerful word processor, and sent from anywhere you can find a phone jack.  The fax cover sheet setup is very versatile, and documents and images faxed through it come out looking pretty good and authentic - a handy thing to have in your pocket for social engineering, or just a good, old-fashioned prank.

The terminal feature is fairly bare-bones, but practical.  It supports speeds of up to 14.4 kbps, but the monochrome LCD has trouble keeping up with speeds faster than 4800 baud.  It supports VT100 and TTY terminals, the former suitable for UNIX sessions.  File transferring is limited to ASCII and XMODEM.  Combine this portable terminal with the decent backlighting, and you've got a machine that might as well have been designed for clandestine Beige Box telecom in some dark alley.

For what it's worth, it also comes with a scaled down version of the Compu$erve software - which I've never used, but might be handy for somebody who has access to it.

Also, the unit supports infrared data transfer, using both IrDA and ASK protocols.  As we're beginning to see infrared appearing more and more in our daily lives (most recently, in parking meters), a feature like this is ripe for street hacking.  My current IrDA project is trying to hack my Furby's brain with it.

And where the Zaurus' small keyboard is a bit awkward to use at first, I've developed a six-fingered keying method and I can pump out about 30 words per minute on it.  Not blazing, but still a lot faster than one can do with the market-standard of stylus-based character recognition.

The Zaurus runs on two batteries of the ubiquitous AA variety.  The manual warns against using NiCad rechargables, citing risks of fire and explosion, but mine hasn't spontaneously combusted in several months of using only them.  If you're maxing it out power-wise (using the terminal or fax with backlighting on), the unit works for about four continuous hours... though they last much longer if you just use it for brief sessions in the other, less power hungry programs, like the scheduler, phone directory, database, spreadsheet, or drawing programs.

The data entered into these features are doubly-secure, so if you lose the unit somewhere, it's not an open book of all your deep, dark secrets.  It can be set up to require a password (up to 7-digits) at start-up - and even then, the unit must be unlocked again in order to show any entries designated as secret.  I'm sure that the boys at Sharp have a backdoor password, though.

Unfortunately, the ZR-3500X does not support many of the after-market software and development tools that come with some of the more upscale Zaurus models.  Programmability is pretty much limited to the spreadsheet function.

So whereas one can easily find many more powerful handheld computer options, most of them list for six to eight times the cost of the Zaurus.  Also, little black boxes tend to be dropped, lost, or have coffee spilled on them sooner or later.  It's just a fact of life.  So getting into the game with a relatively disposable rig helps there, too.

Oh, I almost forgot.  It also has a calculator.