You need tools to develop for the Saturn Game Basic, here they are
Saturn Game Basic Compiler
Game Basic Compiler : The Compiler. Comes from Madrom's Tech CD Runs on Saturn.
Tools to build CD included
Basic filesmust be put in BAS4SS folder
.B file loader included
GraphicsConverter Ver 2.0 : This program allows for the conversion of graphics between BMP and Sega Saturn formats including bitmap variants and textures
Gazo Converter : Converts the bitmap data into the text for Saturn BASIC (32768 & 256 colors support)