The compiler produces code in the fast-load AutoLISP format (FAS). By default, the output file containing this code has the same name as the input file, but with an extension of .fas. You can override the default name by specifying an output file name. For example, to compile yinyang.lsp and produce an output file named GoodKarma.fas, issue the following command:
(vlisp-compile 'st "yinyang.lsp" "GoodKarma.fas")
In most instances, you'll want to specify the full path name of the output file. For example:
(vlisp-compile 'st "yinyang.lsp " "c:/program files/.../sample/visuallisp/goodkarma")
This ensures that the output file is placed in the directory you want..