What is SCASM?

SCASM is a program to develop scenery files for the Microsoft Flight Simulator (version 5.0 and later) and Combat Flight Simulator version 1. The letters "SCASM" are the abbreviated form of SCenery ASseMbler.

Assemblers are low level programming tools which converts every single instruction given in text format to a single instruction in machine (binary) format. SCASM does the same by converting a text file with primitive graphic instructions to a binary file in FS format with the ".BGL" file extension.

SCASM is a program with quite some history. I released the version 0.8 to the public in November 1994 in the CompuServe FS-Forum. But SCASM was not the first published 3rd party program of this kind. BGLGEN by Enno Borgsteede and BGLTOOLS by Hiroo Umeno were published a bit earlier. All these early programs, including SCASM, are created without the suport of the makers of Flight Simulator. For this reason the instruction phraseologiy is different to that of the FS98 SDK which was released later. For backward compatibility of the source code I tried to make as few syntax changes as possible when doing expansions. This is the reason for many odd things in the SCASM syntax.

It is not easy to create working scenery files using only SCASM. But if you 've got a feeling about how to use the instructions, there is nearly nothing you can't do with it. As a matter of fact I was too busy to develop this program to keep the documentation up to date. For this reason there is not enough vacant time to write an tutorial.

To make scenery design easier, other programmers created several graphical front end programs to SCASM. Some of these programs are commercial ones (ASD by Abacus, SCC/Schiratti Control Center by HSP) and others are freeware (Airport, VOD, DOD, MDL2BGL, CfsTmap).

One of the strongest SCASM features is it's ability to handle macros. Using this feature, an experienced designer can even expand the scenery object collection of design programs like Airport, ASD or SCC. VOD by Rafael Sanchez is a well known program to create such macro files without too much knowledge of the BGL graphic instruction language.

The documents for SCASM are only available in english. This is because I hardly have the time to keep ONE set of documents up to date.

It is not allowed to include SCASM in commercial products without a written permission.


Manfred Moldenhauer, author of SCASM, SCLINK & AfdTree
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