by registering as a SIR97 user. An interface to this program is provided in WinGX, which writes a default input file (this may be edited with Edit Sir97File). If the fullpath name for the executable is given in System[Applications], then the interface also launches SIR97.
It is STRONGLY RECOMMENDED that you obtain the latest Windows executable (Release 1.04) since this works satisfactorily in the WinGX environment and with monitors using more than 256 colours (previous versions had a bug in this respect).