The Apple Newton
Development on the Apple Newton began in 1987. The first model of the Apple Newton released was the MP (Message Pad?)100. The Message Pad series PDAs included handwriting recognition. The operating system was known as the Newton OS. The handwriting recognition, early in development was know for not being accurate. A virtual keyboard was also included for typing. Connectivity was achieved via a proprietary serial port. Beginning with the release of Newton OS 2.1 the screen could be turned horizontally for use in landscape mode.
Some applications that were written for the Newton OS included; TapWorks integrated software (Word Processor, Spreadsheet and Graphic software), File Pad database application, a version of Quicken personal finance software. A modem could be attached via the serial port allowing Internet connectivity.
Production of the Apple Newton was discontinued in 1998. There is still a loyal user base that provide support to the Newton to keep it usable.