The idea of making small hand held computer for storing addresses and phone numbers , taking notes and keeping track of daily appointments originated in the 1980’s.

1980 - Psion defined the PDA .

1984 - Psion launched its first organizer, it was slightly longer and thicker than a large pack of cigarettes .

• -  Psion 1 was followed by Psion II

• -  Psion II was followed by a 3a series , which was  the first to link to desktop PC for data transfers.

• - The Series 5 followed up the success of the 3a , Largest screen (640 X 240 pixel) and keyboard to date.

1993 - Apple tried to copy Psion's success,Apple launched the Newton MessagePad One of the first to use touch-sensitive screens and handwriting recognition software .

1995 - US Robotics acquired Palm Computing leading to the launch of the Palm Pilot

1996 - The Pilot was introduced by US Robotics , Data entry was made using a stylus and Graffiti handwriting system (a simplified alphabet for handwriting recognition )

1997 - Apple produced eMate, a new PDA , but handwriting recognition software was not fast enough or reliable enough hence in 1998 Apple discontinued its PDA development.

1997 - US Robotics was bought by 3Com and Palm Pilots became major players in the PDA market , Palm introduced even smaller devices.

1999 - Palm was leading the industry with the Palm V and its Graffiti software, The Palm VII added wireless access to the Internet .Palm Computing's sales for 2001 are estimated at 13 million devices making it the industry's leader .

Types of PDA’s

PDAs fall into two major categories: hand-held computers and palm-sized computers. The major differences between the two are size, display and mode of data entry.

Hand-held computers: Compared to palm-sized computers, tend to be larger and heavier. They have larger liquid crystal displays (LCD) and use a miniature keyboard, usually in combination with touch-screen technology, for data entry.

Palm-sized computers: are smaller and lighter. They have smaller LCDs and rely on stylus/touch-screen technology and handwriting recognition programs for data entry.