Q49394: Example of Passing User-Defined Type from MASM to BASIC

Article: Q49394
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom H_MASM S_QuickASM | mspl13_basic
Last Modified: 5-SEP-1990

The two programs below demonstrate how Microsoft assembly language can
pass a user-defined type to BASIC.

This information about interlanguage calling applies to QuickBASIC
versions 4.00, 4.00b, and 4.50 for MS-DOS, to Microsoft BASIC Compiler
versions 6.00 and 6.00b for MS-DOS and MS OS/2 and to Microsoft BASIC
Professional Development System (PDS) versions 7.00 and 7.10 for
MS-DOS and MS OS/2.

For more information about passing other types of parameters between
BASIC and MASM, search in the Software/Data Library for the following
word:

   BAS2MASM

Code Example
------------

The following BASIC program is BUTYPE.BAS, which receives a
user-defined type from an assembly language program and prints it out:

DEFINT A-Z
DECLARE SUB MasmSub
TYPE mixed
   i AS INTEGER
   l AS LONG
   s AS SINGLE
   d AS DOUBLE
   fx AS STRING * 19
END TYPE
DIM dummy AS mixed
CLS
PRINT "Calling assembly routine which will fill the";
PRINT " user-defined type."
CALL MasmSub
END

SUB BASICSub (dummy AS mixed)
   PRINT "Values in user-defined type:"
   PRINT
   PRINT "Integer: ", dummy.i
   PRINT "Long: ", dummy.l
   PRINT "Single: ", dummy.s
   PRINT "Double: ", dummy.d
   PRINT "fixed-length String: ", dummy.f
END SUB

The following program is AUTYPE.ASM, which builds a user-defined type
and passes it to BASIC:

.MODEL MEDIUM
          usrdefType   STRUC
                       iAsm       DW 10
                       lAsm       DD 43210
                       sAsm       DD 32.10
                       dAsm       DQ 12345.67
                       fxAsm      DB 'Fixed-length string'
          usrdefType   ENDS
EXTRN BASICSub:PROC
.DATA
          BASICRec usrdefType <>
.CODE

          PUBLIC MasmSub
MasmSub   PROC                     ; no stack frame is needed
                                   ;   because no arguments are
                                   ;   passed to assembly
          mov ax, OFFSET BASICRec  ; get address of structure
          push ax                  ; pass it as argument to BASIC
          CALL BASICSUb
          ret
MasmSub   ENDP
          END

To demonstrate these programs from an .EXE program, compile and link
as follows:

   BC BUTYPE.BAS;
   MASM AUTYPE.ASM;
   LINK BUTYPE AUTYPE;

BUTYPE.EXE produces the following output:

   Integer:   10
   Long:      43210
   Single:    32.10
   Double:    12345.67
   fixed-length String:  Fixed-length string

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