Graphical Environment Manager

The Graphical Environment Manager (GEM ) was a graphical user interface of Digital Research, which was primarily known for the Atari ST computer using the operating system TOS. There were also versions for the IBM -PC or a Unix variant. When GEM is largely a replica of the Macintosh interface. The File Manager "Desktop" corresponds to the Apple application " Finder".

Digital Research was sued for GEM by Apple and had to significantly change the file manager " desktop " of the PC version. In particular, the overlapping windows and the recycle bin has been removed. At this time won the competing Microsoft Windows user interface in importance. The judgment that there is a copyright on user interfaces, led to a temporary Apple boycott call by the Free Software Foundation. Later, Apple sued without success the company Microsoft. Not affected by the restrictions was the Atari version, since their development was the responsibility of Atari, which was not prosecuted by Apple.

On the Atari ST series computers of the TOS was also made ​​of the also developed by Digital Research GEMDOS, which was based very closely on the existing CP / M and MS -DOS.

Internal structure

GEM surface usually consists of the following components:

  • The Virtual Device Interface ( VDI) provides device-independent drawing functions (similar to Microsoft's GDI). It is divided into the following sub-components: Drivers for monitor, printer, etc. metafiles (device dependent)
  • Device-independent layer ( GDOS )


For GEM Digital Research yielded predominantly visually -oriented software. These included the word processor " GEM Write", the vector program " GEM Draw", the pixel program " GEM Paint", the bar graph application " GEM Graph", the presentation software precursor " Word Chart".

Later, the word processor was "1st Word Plus" one of the most popular programs.

On the Schneider PC1512 programming language and graphical development environment Locomotive BASIC 2 was included, which in 1986 already made ​​it possible to write simple programs with windows, graphics, mouse support and others.

PC version

Following the acquisition of Digital Research by Caldera the PC version was placed under the GPL. Some enthusiasts did then undo the restrictions (eg they left the desktop program running under GEM 1.x 2.x) and collected old applications, so that PC - GEM today again a reasonably usable user interface for simple, less powerful PCs represents. The usable memory is still limited to 1 MiB. The development of the PC version of GEM is continued under the name OpenGEM or FreeGEM.

Under the name ViewMAX integrated Digital Research a feature- reduced version of GEM in DR DOS 5.0 - about the same time Microsoft delivered its counterpart DOS Shell with MS- DOS.

Atari version

The Atari version of GEM is no longer developed since the disappearance of Atari and is also not free software. Instead, the operating system was TOS, including GEM, componentwise neuimplementiert as free software (see also: MiNT, fVDI, XaAES, TeraDesk ). Also commercial projects emerged (see also: MagiC or Mag X, N.AES! ​​) That even completely replace partly the TOS and only need to boot ( " boot ").

With these new projects, it now also offers multitasking functionality. The change between the individual concurrent programs can, similar to the "classic" Mac OS from Apple ( ie up to and including Mac OS 9) done via entries in the menu bar.