Jaap's Psion II Page

                                 CHAPTER 1

                               ____________
                               INTRODUCTION



The Psion Organiser II is a pocket computer  that  comes  with  a  language
(Organiser Programming language or OPL), several applications, mass storage
and RS232 capability.

The language OPL allows machine code, memory resident extensions.   It  has
database  facilities  for  saving  and retrieving data in a structured way.
OPL code automatically overlays through the procedure structure.  The  code
is  translated  so  the language runs very rapidly, on many applications it
runs faster than an AT running GW BASIC.

The applications that come in the machine's ROM include a simple  database,
diary, calculator and alarms.

Mass storage devices can be plugged in either of the two slots on the  side
and includes 8K, 16K, and 32K datapacks without page counters, 32K, 64K and
128K datapacks with page counters.  32K Ram packs (not a consumer item).

The top  slot  is  available  for  hardware/software  devices.   Psion  has
released  an  RS232, a bar code reader and a magnetic card swipe.  A number
of third parties have already developed hardware devices.

Behind these features, whose  use  is  fully  described  in  the  Operating
Manuals,  lies  the  operating  system and hardware.  This document gives a
complete  description  of  how  the  operating  system  and  hardware  work
together.   The  developer  can then fully utilize the features offered and
extend them.

The intended audience are:

     1.  Application programmers working in OPL (AP).

     2.  Application programmers working either exclusively in machine code
         or a mixture of OPL and machine code (MC).

     3.  Hardware developers (HD).

These titles are used loosely but indicate the general audience intended.
        CHAPTER NAME                    SUGGESTED AUDIENCE
                                        AP      MC      HD
2.      SYSTEM BOARD                                    X
3.      POWER SUPPLY BOARD                              X
4.      TOP SLOT BOARD                                  X
5.      OPERATING SYSTEM                        X       X
6.      MEMORY USAGE                    X       X
7.      KEYBOARD                                X       X
8.      DISPLAY                                 X       X
9.      DATAPACKS                               X       X
10.     SYSTEM TIMING                           X       X
11.     EXTERNAL INTERFACING                    X       X
12.     FILING SYSTEM                   X       X       X
13.     UTILITIES                               X
14.     EDITOR                                  X
15.     MATHS FUNCTIONS                         X
16.     MENUS                                   X
17.     LANGUAGE                        X       X
18.     TABLE INTERPRETER
19.     DIARY                                   X
20.     BUZZER                                  X
21.     ERROR HANDLING                          X