Jonathan Knudsen

Thanks for hosting me this week at JavaRanch. I had a great time and was really pleased to participate in this community.
Best regards,
Jonathan

Hi Lasse,
I think you should probably try a different approach. A MIDlet launching itself every 10 seconds would be very disruptive to the user. See if you can offload this background processing to a server or try some alternate approach. I think you're still thinking in a desktop way and you need to scale down a little for MIDP.

All the Nokias so far have been 1.0. They just announced the 6600, which will be their first MIDP 2.0 device, but it's not available yet.

Actually, there was an announcement from Palm right around JavaOne that they were licensing IBM's JVM and would be packaging it (and MIDP, I think, but not sure if was 1.0 or 2.0) with the Tungsten T. As you can tell, I'm a little sketchy on the details, but you can probably look it up if you want more information.

The book covers the APIs thoroughly but doesn't get into device issues. I believe that there is a lot of this type of information scattered around the Internet, and I agree that it would be very helpful to have a central repository. I've been giving it some thought but haven't come up with a plan yet.

MIDP's application model doesn't really specify whether you can have multiple MIDlets running simultaneously. It's up to the implementation. I believe my Nokia 3650 does allow MIDlets to run simultaneously, but I'm sure my Motorola i85s does not. At any rate, the specification doesn't guarantee that MIDlets can run simultaneously, so you can't count on it.
That being said, you may be able to achieve the functionality you're seeking regardless. MIDP 2.0 offers two features that may do what you want. The first feature is the ability to request that a MIDlet be run at a certain time. This is great for ticklers or appointment book applications.
The second feature is the push registry, which allows MIDlets to register interest in incoming network connections. When the phone receives such a connection (incoming SMS message, maybe) it launches your MIDlet and you get to handle the incoming connection.

You can find out whether pointer events are supported by calling the hasPointerEvents() and hasMotionPointerEvents() in the Canvas class. If these are supported, then your Canvas subclass will be notified via the pointerPressed(), pointerReleased(), and pointerDragged() methods in Canvas.
If pointer events are crucial to your application but not supported on the device, you will need to provide an alternate method of input, probably based on keys.

Well, they're supposed to be directly portable, so anything you write that complies with the MIDP specification should run on any MIDP phone. In reality, there are implementation differences and outright bugs. I hear a lot of complaints from developers who are having trouble running an application on multiple devices.
However, the alternative (writing native and porting to each different platform) seems even worse. I think that's the secret to MIDP's success, that it's easier to tweak a MIDlet to run on multiple devices than it is to port a native application.

Layne-- did you try "-target 1.1" as Michael suggested? I think that should fix the problem you're seeing with preverify.

With regards to embedded programming, you might want to check out the Information Module Profile (IMP), which is basically MIDP without the UI stuff:
http://www.jcp.org/en/jsr/detail?id=195

MIDP 1.0 supports pointer events, but it depends on the device. Most cell phones don't have touch screens, but there are a few exceptions: Palm OS devices, Sony Ericsson P800, possibly others.

Yes, the stuff for the phones is on its own track. In the Java universe, there's J2EE for enterprise applications, J2SE for desktop applications, and J2ME for small devices. Most of J2ME is developed as Java Specification Requests (JSRs) under the Java Community Process (http://jcp.org/).
For an overview of wireless Java, see:
http://wireless.java.sun.com/getstart/

Here's a good starting point for the "big picture":
http://wireless.java.sun.com/getstart/

MIDlets can do HTTP, which gets you to a servlet. With a servlet, you can do anything. I think that's the basis of building powerful applications with MIDP. Most of the power is in the server, probably, but MIDP gives you a chance to make a compact mobile client.

I don't know what jascii-v1.0.20 is, but it sounds like you need to include the MIDP classes in your classpath.