Handheld technology: the basics
A brief history of handheld computers and a look at how they work, including a look at operating systems and input and output devices.
What is a handheld computer?
Handheld computers include those devices originally referred to as personal digital assistants (PDAs) and others that have evolved from that concept. These devices now offer many more computing functions than the original PDAs, which mainly included calendars, address books, and “to do” lists. These devices range in size from those that fit into one hand and use a stylus for input to those with keyboards that are approximately 1/2 to 1/3 the size of a typical laptop. The term
How they evolved
Apple Computer, Inc. developed the Apple NewtonTM in 1993. The company introduced it as the first PDA and sold it as the ultimate information appliance. John Sculley, former chairman of Apple, predicted PDAs would become ubiquitous tools that would hold telephone numbers, keep calendars, store notes, and send and receive data wirelessly. Unfortunately, the Newton was ahead of its time and did not find a market large enough to survive.
In 1996, Palm, Inc. delivered the first truly successful handheld computer, the Palm Pilot. This device helped people organize their lives by providing instant, anytime access to schedules, important phone numbers, addresses, “to do” lists, and other key information. The business world quickly embraced the small and powerful Palm handhelds.
Because of the popularity of the Palm Pilot, several other manufacturers began releasing their own PDA devices. These devices utilized a new operating system from Microsoft called Windows CE, which was basically a scaled-back version of the Windows desktop environment. The most recent version of Windows CE is now called Pocket PC.
Most of the producers of PDA-type devices are trying to encourage the public to think of these devices not as PDAs but as handheld computers. Many producers are not only adding on computer-type capabilities but also combining their devices with other electronics, such as wireless phones, cameras, and probes.
How they work
Operating systems
While there are many handheld manufacturers in the market these days, there are really only two major operating systems in direct competition at the time of this publication: the Palm OS’ (used by Palm, Handspring, and Sony manufacturers to name a few) and Windows CE/Pocket PC (used by Hewlett Packard, Compaq, Casio, NEC, Toshiba, etc.). In general, the Palm OS represents a more basic approach, and the devices are cheaper. The Windows CE/Pocket PC system is more robust, and the devices are generally more expensive and, due to their more complex system, require more technical support.
Currently, handheld devices using the Palm OS have approximately 75% of the market share; however, there are advantages and disadvantages to both operating systems, and the decision to use one or the other depends upon users’ needs. Other handheld operating systems being used today include Symbian, used in cellular phone technology; RIM, used in the BlackBerryTM line of handheld devices; and the Psion EPOC system.
Input
There are a number of options for entering data into a handheld, depending on the model:
- Onscreen keyboard. The user punches letters and numbers on an onscreen representation of a standard keyboard.
- Character recognition program. The user “handwrites” data using the stylus (e.g., Graffiti for Palm OS and Character Recognizer for Windows CE/Pocket PC).
- Synchronizing. Since handhelds don’t have floppy drives to transfer data and programs, they must be “synched” with a desktop/notebook computer. This is done with a program installed on both devices (HotSync for Palm OS and ActiveSync for Windows CE/Pocket PC) and a connection between the devices. Depending on the model, this can be done using a cradle, a cable connection, or wirelessly. During synching, schedule and address book information, e-mails, and other specified data are shared between the devices. Synching is also used to install new software on a handheld device.
- Memory-stick. The latest models of the Palm OS technology allow data to be shared through memory sticks. These postage-stamp-size memory modules can be easily inserted into the handheld unit for access to pre-recorded applications and data or used to store additional data as one would with a floppy disk or CD-ROM.
- Infrared port. Most handhelds have an infrared port that allows users to “beam” or wirelessly transfer programs and data between handheld devices. The infrared port is considered by many to be a major advantage in educational use. This process requires a fairly close proximity between the devices and a clear line of sight.
- External keyboard. There are many models that attach to handhelds to allow full-size typing capabilities.
- Other peripherals. Data can also be input with probes, modems, network cards, cameras, and many other add-on peripherals.
Output
There are also many ways to output data from handhelds:
- Screen. Screens are the most common output method for handhelds, and they vary widely in size, resolution, and readability.
- Infrared port. See Input, above.
- Synchronizing.Data can be sent from the handheld back to desktop computers for further manipulation.
- Peripherals. Data can be output to peripherals, such as memory sticks, modems, network cards, and printers.
