Topic       : TOS - The Operating System
Author      : 
Version     : tos.hyp (December 19, 2008)
Subject     : Programmieren/Atari
Nodes       : 3010
Index Size  : 93790
HCP-Version : 5
Compiled on : Atari
@charset    : atarist
@lang       : 
@default    : Title
@help       : 
@options    : +g -i -s +x +zz -t4
@width      : 70
View Ref-File2.2  GEM                                                           TOS

GEM (Graphics Environment Manager) is a part of the operating system 
that represents the (graphical) interface between the computer and the 
user. GEM was developed by the firm Digital Research in 1984 for PCs 
with Intel processors. The system became well-known, however, mainly 
when the Atari ST was marketed, offering a powerful and well- priced 
alternative to the (at the time) expensive PC and Macintosh machines.

In the course of time, GEM was adapted to various operating systems 
and hardware platforms, including:

   . PC GEM
   . Atari GEM
   . GEM on X (version for Unix systems)
   . X/GEM, for FlexOS operation system

GEM may be divided into two sub-areas:

   . AES, Application Environment Services
   . VDI, Virtual Device Interface

The AES takes charge of organising the user environment, whereas the 
VDI looks after a uniform graphical rendition of the user interface. 
During development of GEM programs it is imperative to keep to the 
valid style guidelines and never attempt to force on the user one's 
own interface 'surface' that doesn't keep to any standards.