Interrupt, InterruptX Routines
 ----------------------------------------------------------------------------


 Action

 Allow BASIC programs to perform DOS system calls.


 Syntax



  CALL  Interrupt ( interruptnum%,  inregs,  outregs)


  CALL  InterruptX ( interruptnum%,  inregs,  outregs)

 Remarks

 The  Interrupt routines use the following arguments.

-----------------------------------------------------------------------------
 Argument                                Description
 ----------------------------------------------------------------------------
  interruptnum%                          A DOS interrupt number that is an
                                         integer between 0 and 255.

  inregs                                 The register values before the
                                         interrupt is performed;  inregs is
                                         declared as type RegType or
                                         RegTypeX. The user-defined types
                                         RegType and RegTypeX are described
                                         below.

  outregs                                The register values after the
                                         interrupt is performed;  outregs
 Argument                                Description
 ----------------------------------------------------------------------------
                                         interrupt is performed;  outregs
                                         is declared as type RegType or
                                         RegTypeX. The user-defined types
                                         RegType and RegTypeX are described
                                         below.



 The following statement defines RegTypeX.

 TYPE RegTypeX


 AX AS INTEGER


 BX AS INTEGER


 CX AS INTEGER


 DX AS INTEGER


 BP AS INTEGER


 SI AS INTEGER


 DI AS INTEGER


 FLAGS AS INTEGER


 DS AS INTEGER


 ES AS INTEGER


 END TYPE

 The following statement defines RegType (the DS and ES registers are not
 included).


 TYPE RegType


 AX AS INTEGER


 BX AS INTEGER


 CX AS INTEGER


 DX AS INTEGER


 BP AS INTEGER


 SI AS INTEGER


 DI AS INTEGER


 FLAGS AS INTEGER


 END TYPE

 Each element of the type corresponds to a CPU element.


  InterruptX uses the values in the DS and ES registers. To use the current
 values of these registers, set the record elements to -1.

 The  Interrupt and  InterruptX routines replace the INT86 and INT86X
 routines used in earlier versions of BASIC. They provide a more convenient
 way for BASIC programs to use DOS interrupts and services.

 To use  Interrupt or  InterruptX in the QBX environment, use the QBX.QLB
 Quick library. To use  Interrupt or  InterruptX outside of the QBX
 environment, link your program with the QBX.LIB file.

 The QBX.BI header file contains the necessary declarations for  Interrupt
 and  InterruptX .


 Note

 The  Interrupt and  InterruptX routines are not available in OS-2 protected
 mode. For OS-2 protected mode, replace  Interrupt with the equivalent OS-2
 function invocations. For more information about doing OS-2 calls from
 BASIC, see Chapter 14, "OS-2 Programming" in the  Programmer's Guide.


 Example

 The following example uses  Interrupt to determine the current drive and the
 amount of free space remaining on the drive.

 To use  Interrupt, you must load the Quick library QBX.QLB using the -L
 option when you begin QBX. You also must include the QBX.BI header file as
 shown below.

 ' $INCLUDE. 'QBX.BI'


 DIM regs AS RegType' Define registers.





 ' Get current drive info.


 regs.ax = &H1900


 CALL Interrupt(&H21, regs, regs)


 ' Convert drive info to readable form.


 Drive$ = CHR$((regs.ax AND &HFF) + 65) + "."





 ' Get disk's free space.


 regs.ax = &H3600


 regs.dx = ASC(UCASE$(Drive$)) - 64


 CALL Interrupt(&H21, regs, regs)


 ' Decipher the results.


 SectorsInCluster = regs.ax


 BytesInSector = regs.cx


 IF regs.dx >= 0 THEN


 ClustersInDrive = regs.dx


 ELSE


 ClustersInDrive = regs.dx + 65536


 END IF


 IF regs.bx >= 0 THEN


 ClustersAvailable = regs.bx


 ELSE


 ClustersAvailable = regx.bx + 65536


 END IF


 Freespace = ClustersAvailable * SectorsInCluster * BytesInSector





 ' Report results.


 CLS


 PRINT "Drive "; Drive$; " has a total of";


 PRINT USING "###,###,###"; Freespace;


 PRINT " bytes remaining free."