This operation code determines if the WIN$PRINTER routine is supported (i.e., the host machine is a Windows machine).
CALL "WIN$PRINTER" USING WINPRINT-SUPPORTED GIVING RESULT
This operation sets the return value of WIN$PRINTER to 1 if the WIN$PRINTER routine is supported. Otherwise it sets the return value to WPRTERR-UNSUPPORTED.
The WIN$PRINTER routine can only be used with Microsoft Windows.