PDA SOUP

Dick Pountain/Tue 18 March 2003/1:57 pm/Idealog 104

I heartily endorse Jon Honeyball's opinion - see this month's Advanced Windows - that we're witnessing the unfolding of a new era in computer technology, one in which content finally takes precedence over form. This is thanks to the prospect of widespread XML as the 'universal' data exchange format, and to Microsoft's belated introduction of a database, rather than file, oriented file system for the Longhorn version of Windows. If I don't seem quite so overtly excited by this vision, that's only because I've been using my Palm PDA daily for the last six years, and Palm OS has always taken what is now being called a 'digital soup' approach to data storage. It's ironic that many techie-minded Palm purchasers have regarded this innovative operating system with contempt - it's just too simple - and wanted something that's more like old file-based Windows (a loss of technical nerve that Microsoft ruthlessly preys upon to advance its stale old PocketPC platform). 

 To avoid accusations of rewriting history I really should give credit where it's due by genuflecting in the direction of Apple's now defunct Newton, which pioneered this notion of an object-oriented soup of data from which titbits are retrieved on demand by clever search software. The concept proved too ambitious to run on 1993 hardware and so Newton failed commercially, but the original Palm Pilot was born directly out of its ashes. Palm took a far more restricted but realistic approach to what could be delivered in a handheld package, but the one thing it did retain from Newton's agenda was an operating system that's at root a database, in which the concept of a file is almost entirely hidden from the user.

For as long as I can remember (which means pre-CP/M days) novice computer users have been turning on their machine for the first time and then scratching their heads over how create a document - first they need to understand what a text editor or word-processor is, then what its precise name is and where the operating system has hidden it. Files have never been a great way to store data from an end-user's point of view: they were invented to make life simple for the operating system. Maintaining file associations under Windows so that files open upon clicking their name has always been crude and tricky. You have to do it from a well-hidden and obscure submenu (View | Folder Options | File Types) whose dialogue is a techie hell and quite terrifying to the novice (WTF is a DDE or a MIME-type?) Those few default associations that Microsoft does provide are, unsurprisingly, only with its own Office components, while third-party developers get lynched if they steal these file associations for their own products. And if you want to associate a particular file with more than one application, forget it.

The digital soup concept means you never see the files themselves, because the surface the operating system presents to you is all about data creation and retrieval. The Palm for example presents hardware buttons, the most immediate possible form of interaction. Want to create an appointment - press the Datebook button and just do it. Where's that appointment stored? Why would you care? The Datebook application saves its data automatically whenever you move to some other application, and it gets backed up every time you Hotsync with a PC. Years of wrestling with PC software can actually get you addicted to anxiety and confusion (or 'problem-solving' as the euphemism has it), which I guess makes PocketPC the equivalent of Methadone... 

Palm OS is in many ways a technically simplistic operating system, most particularly in the area of multitasking - basically it can't, it just switches contexts, though that's hardly surprising when it has to work with around one hundredth of the memory space and CPU cycles of a Windows PC. Nevertheless its file system anticipated Longhorn  by years in that it's basically a database engine dealing in records rather than streams of raw bytes. The internal structure of Palm OS databases is not so rich as XML will be on LongHorn (that is, able to expose the structure of its data externally) but it does mean that all Palm OS data shares a similar internal format, accessible in the same way through record PUT and GET operations.

What's slightly disappointing is how few current Palm applications make use of this fact that, say, the Memo Pad and Address Book are available from the 'soup' to be consulted or manipulated. It's not that difficult because I do it myself using the CASL development system (www.caslsoft.com). I first used CASL years ago when it was still in beta, but on returning recently to version 3.3 I've found it a stable and able programming platform, as good as a Visual Basic for Palm. And it gives you full access to the built-in databases, so I often write utilities that save their data as Memo records to simplify exporting to my PC. On principle all my utilities employ persistent data that's automatically saved when you leave and restored next time you start. CASL lets me develop on my Windows machine, with excellent debugging facilities, but for testing in a full Palm environment the Palm OS Emulator is also indispensible (www.palmos.com/dev/tech/tools/emulator/): nowadays it supports multiple ROM images and skins so I can change it from, say, a CLIE to a Palm 100 with one click, which still seems a bit like magic.