atalan.exe is command line utility. Specify name of source code to compile as an argument (source come nust have .atl extension, it is not necessary to specify it in argument). The compiler will generate file *.asm. If mads.exe is in the same directory as the compiler, *.asm is automatically compiled and *.xex is produced.
You may specify following switches (each after minus):
stars.asm, stars.lst and stars.xex will be generated. Resulting binary file may have different extension than xex, if the target platform is not Atari.
To compile hello_world for Atmos platform, type
atalan -p atmos hello_world