BBC BASIC Programmers' Reference

by Richard Russell, October 2015

Disk drives (including internal and external hard drives, USB flash drives etc.) have two kinds of serial number. One is the volume serial number which is created when the drive is formatted, and can later be changed, and the other is the hardware serial number which is assigned by the manufacturer and cannot be changed (at least, not in a straightforward way). The volume serial number is easily discovered (e.g. using the GetVolumeInformation API function) but finding the hardware serial number is more tricky.

The program below lists the hardware serial numbers of each of the mounted drives in the system:

      INSTALL @lib$+"COMLIB"
      PROC_cominitlcid(1033)

      ON ERROR PROCcleanup : SYS "MessageBox", @hwnd%, REPORT$, 0, 0 : END

      objSWbemLocator% = FN_createobject("WbemScripting.SWbemLocator")

      objWMIService% = FN_getobject(objSWbemLocator%, \
      \                            "ConnectServer(""."", ""root\CIMV2"")")

      objSWbemObjectSet% = FN_getobject(objWMIService%, \
      \                "execQuery(""select * from win32_physicalMedia"")")

      nObjs% = FN_getvalueint(objSWbemObjectSet%, "Count")
      IF nObjs%=0 ERROR 100, "No disk drives present"

      SYS !(!objSWbemObjectSet%+28), objSWbemObjectSet%, ^pEnum%
      IF pEnum%=0 ERROR 100, "SWbemObjectSet::NewEnum failed"

      DIM Variant{(nObjs%) type%, pad%, ldata%, hdata%}

      SYS !(!pEnum%+20), pEnum% : REM IEnumVARIANT::Reset
      FOR i% = 1 TO nObjs%
        SYS !(!pEnum%+12), pEnum%, 1, Variant{(i%)}, ^celtFetched%
        IF celtFetched%<>1 ERROR 100, "IEnumVARIANT::Next failed"
      NEXT i%
      SYS !(!pEnum%+8), pEnum% : REM IEnumVARIANT::Release

      FOR i% = 1 TO nObjs%
        PRINT "Drive ";i%;" serial number is: ";
        dummy% = FN_getvariant(Variant{(i%)}.ldata%, "SerialNumber", _ret{})
        IF _ret.vartype% = 8 THEN
          PRINT _ret.data$
        ELSE
          PRINT "Not available"
        ENDIF
      NEXT i%

      PROCcleanup
      END

      DEF PROCcleanup
      PROC_releaseobject(objSWbemLocator%)
      PROC_comexit
      ENDPROC