Data Entry
Graffiti
When you first put batteries into your Palm OS device, MemoPad showed a memo describing ways to enter data. Graffiti, the “handwriting” of Palm OS devices, was last on the list.
This guide covers Graffiti first—because it is an easy, high-speed way to enter data into your Palm OS device, and requires nothing more than the Palm OS device itself.
Rather than attempt to have the device
understand the various letterforms people produce, the Graffiti
technique uses a specific set of letterforms that are recognized and
requires you to use them.
However, with some exceptions, the Graffiti letterforms are block
letters: uppercase printing.
The Graffiti recognition engine is also quite forgiving of rounded
corners and recognizes several alternate letterforms made with a
single stylus path.
The alternate letterforms (such as a continuous path for the letter
“x,” a simple curved path for the letter “y,”
and two-component path for the letter “v”) are documented
on the web, but frequently not in anything that comes with the Palm OS
device.
Even with pauses to correct an occasional mis-recognized letter, you should be able to Graffiti faster than you can legibly print. Graffiti has the advantage that your text needs to be understandable to only one audience—the Palm OS device—only once; thereafter it is represented by either neatly formed letters (on the screen) or computer data.
Using Graffiti to enter an occasional appointment or telephone number into your Palm OS device requires only what came with your Palm device. In fact, for occasional or casual data entry, the on-screen keyboard may be even more effective than Graffiti, as you will not need to learn the Graffiti letterforms. However, entering large amounts of text into your Palm OS device will be much easier on you with a good stylus, and much easier on your Palm OS device with a screen protector. Styluses and screen protectors are discussed in previous sections of this web site.
The design of Palm OS devices’ pressure-sensitive screens deserves mention here, as certain habits of Graffiti entry can inadvertently shorten the life of your Palm OS device. The device screen consists of two layers of glass or plastic with a conductive coating, separated by a thin layer of non-conductive jelly. One layer is charged, and the voltages at the edges of the other is measured. Tapping or touching the stylus to the screen pushes the jelly aside and brings the two conductive layers into contact. The resulting voltage at the edges of the second layer depends on the distance from the edge to the point of contact—which is the stylus position. The device measures the voltages and determines the stylus position. When the stylus is raised, the jelly flows back into place, the circuit is broken, and the device can tell the stylus is no longer touching the screen.
This design is elegant and effective, but not particularly durable. Over time, the jelly tends to migrate away from the area of highest pressure—the Graffiti entry area. When this happens, the stroke you make and the stroke the device detects become less like one another, and Graffiti recognition becomes finicky, unreliable, or altogether impossible.
You can delay this condition by making your Graffiti strokes light: use the least amount of pressure that still enables good recognition. It may help to consider the stylus to be a type of brush, rather than a type of pen: the delicate touch you would use with a fine artist’s brush while painting is similar to the touch you should use when using Graffiti. You can also delay this condition by using a keyboard, miniature keyboard, or PC for large data entry sessions. Folklore holds you can to some extent reverse this condition by gently but firmly dragging your fingertip from the far edges of the screen to the center of the Graffiti area, for several minutes. This is said to help return the jelly to the Graffiti area.
In summary, Graffiti is an easy, high-speed data and text entry mechanism. It requires nothing that does not come with your Palm OS device. If you use your Palm OS device extensively for data and text entry—such as writing the next Great American Novel in your spare time—the addition of a stylus and screen protectors is essentially mandatory, and a keyboard or miniature keyboard is highly advisable.
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Copyright © 2002 Brian Hetrick
Page last updated 15 July 2003.
