Why Java on DoCoMo could be very SlowCoMo

Calling Spectrum programmers...

In a few weeks the giant Japanese telco DoCoMo will begin to ship its next generation of i-Mode Java-enabled phones. We mentioned this in passing recently, prompting an unexpectedly large postbag to The Register.

Rightly, many of you smart people told us that these 503i devices really do represent the first mass market platform for Java, after years of effort by Sun trying to it the unlikeliest consumer appliances. Trouble is, this won't be Java as we know it. Or at least not just yet.

These phones run KJava, the latest and certainly smallest variant of Java that Sun has specified. Given the sheer number of small-footprint Javas which Sun has released - and it flings them out with the indiscriminating enthusiasm of a clay-pigeon machine - that's quite something.

But DoCoMo has gone to particular trouble to make sure that the user expectations are kept under control. The Java applets will be limited to 10k in size, with 5k of memory available as scratch. KJava runs on one thread in this environment, and doesn't map natively to the embedded OS' threading model.

When we heard this the first time round we were sceptical, but a second source confirms this, adding that this isn't because of any particular limitations in KJava - which has been designed with scaling in mind- but rather for technical reasons. DoCoMo doesn't want millions of its users trading large applets.

So it looks like veterans of early 80s micros could find their finely honed programming skills back in use. Only this time, you won't need to run off a cassette tape.

The initial applications are likely to be games, and instant messaging, and Sony has apparently worked out a trick to display information from the handset onto a TV via its games consoles.

And what will the Japanese do with these? This was best described in the following gem we culled from one of the more obscure Asian business wires, and which has a weird poetry in its own right:-

"For example, users might want to raise virtual pets or other animated characters using their phones, and then later use a TV to show their friends what they've done, or else to let the characters fight each other."

It may be 10k... but all human life is in there. ®

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