Some thoughts on Personal Digital Assistants

Firstly, let me suggest that there is a significant difference between a PDA and a Handheld Personal Computer (HPC).

The concept of a PDA, as coined by John Sculley and created by Apple with the Newton MessagePad, has some fairly basic properties that distinguish it from desktop computers.

Screen

The available screen real estate of a PDA will always be smaller than what is possible to support in an essentially stationary device.

Storage

PDAs cannot be expected to equal the storage capacity of a desktop machine which has greater physical size and mains power.

Expansion

Without the physical room to support a standard bus and/or drive bay system of expansion, PDAs will be less expandable and upgradeable than a desktop (or even laptop) machine.

Baring these limitations in mind, what can a PDA usefully do?

Use of PDAs

Since owning a Newton, I have found that I use in three basic scenarios:

Tethered

At my desk, either at home or work, where the Newton is connected to the transformer and could be connected serially with minimal effort.

Roaming

At home or in a workplace, but not at my desk. Normally at someone else's desk or in a meeting. This situation is distinctive in that it is feasible to consider a reasonable bandwidth wireless connection.

Elsewhere

Neither at home, nor at work. In the bus, at a restraunt, etc. In this case, cellular modem is probably the best bandwidth that could be achieved, and that at relatively high cost.

Proposed Extensions for Newton OS 2.x

Address Book

• Synchronise with a similar thing under Unix. Newtonlink uses xrolodex, but this is of minimal use to me: I am primarily interested in synchronising my mh aliases file with the email addresses on the Newton. Similarly, I'd like to have the phone numbers move into xphone's databases, and groups synchronise with a group mail alias or majordomo list, or something.

  Part of the problem here is that I don't use anything similar under Unix already - basically because it is useless to me when I normally need this sort of information. I do have a list of email aliases however, and there is a company phone database.

• Automatically extract people's names and other info from received email. This should also attempt to decide what company the person works for and create an appropriate link (and the company itself if necessary).

• Support a format for encoding person, company and group information in email. The vCard standard is probably the one to beat here.

Calendar and Diary

• Synchronise with a range of packages under Unix. The worst thing about these packages at the moment is that they are never up to date because they're not with me when I find out about meetings.

• Support a format for embedding meeting info in email. I need to be able to send and receive mail requesting meetings and have it entered automatically. Again, the vCalendar format is probably the go here.

Web and File Access

• It is desirable to support a web browser: more and more information that I need is kept on the web. That said, it needn't be full-featured. I don't need: sound, plug-ins, coloured text, fonts, ...

  On the other hand, tables are mandatory and frames are becoming more useful (although not necessary yet).

  It's my belief that the best approach is to run a slave daemon on a desktop system which handles the fetching and does some transformation of the info before passing a pre-parsed structure down to the PDA. Using this approach, we can transform all images to a single supported format; grab the first image from a animation; strip font, text colour, background images and so forth before handing it over to the PDA for rendering.

  With the support for file:/ URLs, the other vital information access need is also met: local filesystems.

  The system must support standard cut and paste to the Newton notepad, and other applications. It'd be cute if there was some format translation done too (so you could retain the HTML) but ...

• An interesting design issue is whether this could be integrated as a stationery type in the notepad. I see no reason why not, and it might be nice to retain documents offline in a created "note" of type "Web" (or something).

Email

Usenet News

Pager

Locator

Unix Notepad Translator

One of the most useful features of the Newton is the Notepad's ability to store mixed text and images. However, once done, there is no useful way of handling these objects on a desktop machine.

The only widely used format that is vaguely capable of handling such mixed media objects is a web page. With appropriate use of tables and images, the contents of a Notepad page could be rendered into HTML. While there is still no good editor for these pages on Unix, at least it's viewable ...

Of course, it would then be necessary to support a reverse translation, from HTML to Notepad. This is of course useful in itself, and ties in with the cut and paste formating for the web browser.