Introduction To The EPOC Platform

EPOC is the first truly communication centric operating system for mobile information platforms. It is not constrained by being a down sized PC operating system or a 16 bit architecture. It harnesses the full potential of object-orientation to deliver a powerful set of user and developer tools from a small ROM footprint. Its three tier architecture means it can be delivered on a range of chip sets and allow device manufacturers to deliver unique and ergonomic interfaces. With support from several leading mobile phone vendors and a growing base of licensees (to which Sony is the most recent edition) EPOC will undoubtedly be a major player in the wireless market place.

In this article we will explore the evolution of EPOC from Psion's Organiser of the mid 80's to the creation of Symbian and beyond. Then we will briefly review the features seen by most users, the underlying architecture and the options for developing EPOC applications.

Psion and the Series 3

Formed in 1981 Psion initially developed a successful flight simulator for the Sinclar ZX Spectrum. The cash generated from this product was used to create a database orientated pocket computer. The Organiser was launched in 1984 and updated 2 years later. It had 32k of combined ROM and RAM and implemented a diary, database, clock, alarm, calculator and simple BASIC-like programming language called OPL (Organiser Programming Language). The Organiser proved to be a success for Psion and formed the basis for the company's future direction.

In 1988 Psion was floated on the UK stock market. Cash-rich Psion then embarked on a replacement for the Organiser. The SIBO (16 bit Organiser) operating system was developed and in 1990 the MC laptop introduced. However the product was largely a failure as the hardware was unreliable and practical PC laptops were appearing on the market which delivered more powerful features.

While the product failed from a commercial standpoint, SIBO was nonethless perceived as a powerful product. Its small footprint of 384Kb delivered a full suite of applications except, notably, a spreadsheet. It could run practically on 128Kb of ROM and provided full multitasking, allowing the user to instantly switch between running applications. Psion therefore shifted their focus to a smaller device. This rethinking resulted in the Series 3 in 1991 with options to develop in C, x86 assembler or OPL. Uniquely, OPL could be developed directly on the Series 3 without the need for a PC, which resulted in a proliferation of games and applications from independent developers. The Series 3 was developed over the next 7 years; in 1993, the 3a introduced the missing spreadsheet application; in 1996, the 3c introduced a built-in IR port; the Siena introduced a calculator pad along side a smaller screen. Finally, in 1998, the 3mx was introduced with a significantly faster processor. Also, during 1995, PC synchronisation software PsiWin was introduced allowing data to be exchanged with PC applications.

The Series 3 was successful for several reasons. The robust operating system rarely crashed (this author's machine ran without rebooting for almost 4 years!). It also sported very low power usage, with two AA batteries providing at least a month of normal usage. It also provided a rich set of applications which, despite the lack of pen or mouse, were easy to use and, finally, reliable, functional hardware. Also significant was that most rival products suffered from problems, including poor keyboards, unintuitive user interfaces and temperamental power management.

SIBO and the Series 3 did have its limitations. The obvious problems with a 16 bit architecture were recognized, while the hardware lacked a pointer type input mechanism and the expansion slots were proprietary.