How Personal digital assistant Works

Personal digital assistant

It seems as though everyone is using a PDA these days. These little devices have virtually replaced bulky planners, desk calendars, address books, and other organizational tools, and yet, you resist. If you’ve decided that you want to jump into the 21st century and start using this handy device, here is some information to help get you up to speed.

PDAs, or personal digital assistants, have been on the market since 1996 when Palm Computing Company introduced the first model, the Palm Pilot. But the history of the PDA goes back to the early 80s when Psion introduced a small organizer called the Psion 1. At the same time, Apple Computers introduced a hand-held computer, the Newton Message Pad, but it was considered to be much too large and very expensive.

In 1986, Jeff Hawkins, who would ultimately become the founder of Palm Computing, took a leave of absence from his job at GRID Computers to do some research at U.C. Berkeley. He had a vision and, while at Berkeley, he did some early work with software that would allow for the integration of written characters and a computer. When he returned to GRID, he began working on the prototype for today’s PDA, a product called the GRIDPad. The device, while functional, had a hefty price tag, listing for over $2500. This development was followed by Microsoft’s introduction of “Windows for Pen Computing” in 1991.

Hawkins was not satisfied with his model, however, realizing that it was both too large and too costly to appeal to the mass market. He began working on a plan and, as a result, in 1992 he founded Palm Computing. Palm partnered with several other companies, including Casio, which had signed on as the manufacturer, and the company’s first product, the Zoomer,was introduced in 1993. The Zoomer was less than successful, in that it contained too many features, and was still too big and too expensive. It was also quite slow.

The second generation of the product, which was faster and designed so that the user could utilize a special pen to enter data, still did not capture the public’s attention and, ultimately, Casio decided to withdraw their partnership. It was then that Hawkins made the decision to handle the entire project himself, without depending on outside resources.

Hawkins’ goal was clear. He wanted to make sure that the product was small enough to fit into a shirt pocket, and that the price was under $300. The device had to interface with a computer and be simple enough for the average user to operate. He insisted that the product be fast and completely interactive. He crafted a wood model of the device and began carrying it around with him, getting the feel of using it. This model became the template for the original.

Palm received some additional funding and had an aggressive business plan calling for delivery of the finished product to market within 18 months. Although there were some minor setbacks along the way, the device was finished in the fall of 1995. However, in order to get the funding necessary to go into the manufacturing phase, Palm began soliciting investors.

In 1995, US Robotics made an offer Hawkins could not refuse and acquired Palm Computing. Again, difficulties in the manufacturing process delayed the introduction of the product to market, but, in April 1996, the first Palm Pilots were shipped for sale. By the end of 1996, customers had discovered the product and the rest, as they say, is history.

Today’s PDA operates on the same basic principals but has benefited from improvements in technology. All PDAs use microprocessors, similar to those used in PCs and laptops. But the microprocessors in a PDA are much smaller and, as a result somewhat slower. Early on, Hawkins decided to sacrifice some speed to keep the price lower and the unit smaller.

Rather than using a hard drive, a PDA relies on a ROM (read-only memory) chip for program storage and a RAM (random-access memory) for storage of data entered by the user. Most PDAs are set up with 2MB of memory, allowing for the storage of 8000 phone numbers and 200 email messages. Palm has its own operating system, Palm OS, which is much smaller than a standard operating system used by a PC. Early on, Jeff Hawkins specified all of these features as part of the original design.

All PDAs have an LCD screen. This screen is used for both inputting data and reading stored data. They can be either black and white or color, and feature either a reflective or backlit screen. Look for an active matrix display rather for ease in reading data and images.

A PDA is furnished with a stylus, which is a special interactive pen, along with a touch screen. The screen actually has several layers, with the top layer consisting of a thin sheet of plastic or glass. Under that layer is a layer of oil, which is on top of another layer of glass that is lined with vertical and horizontal bars.

When the stylus is applied to the screen, the tip of the pen pushes through the oil level, touching the glass. This action changes the voltage field and sends current through the vertical and horizontal bars on the screen. The PDA recognizes the coordinates of the point where the stylus touched down and reacts by launching the application that was selected.

Handwriting is recognized by a software program called Graffiti. This program requires the use of a special alphabet developed especially for the PDA and numbers and letters must be entered one at a time. Some people find this difficult to learn, however, and prefer to use the integrated keyboard.

PDAs are designed to communicate with your laptop or desktop PC. This is accomplished by using either a USB or, in older models, serial port on the PDA. Also, newer units feature wireless data transfer as well modem accessories. Setting up the PDA with your computer is relatively simple. Most PDAs include software necessary to do this installation and data can be synchronized allowing copies of all files to be backed up on your computer.

Unlike the early PDAs, today’s version is compact and relatively inexpensive. Jeff Hawkins certainly knew his market and today’s product, although faster and with more features, bears a surprising resemblance to his original design. If you find yourself lacking in organization and looking for the perfect solution, the PDA could be the solution you’ve been looking for.

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