Q64429: Example of Assembly Function Returning Integer to BASIC

Article: Q64429
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 SR# S900718-12 | mspl13_basic
Last Modified: 5-SEP-1990

The two programs below demonstrate how an assembly language function
can return an integer to a Microsoft BASIC program.

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, query in the Software/Data Library or this Knowledge
Base for the following word:

   BAS2MASM

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

The following BASIC program is IFUNC.BAS, which displays an integer
returned from an assembly language function:

   DECLARE FUNCTION QPrint%
   FOR i% = 1 to 5
      PRINT QPrint%
   NEXT

The following assembly language program is AINT.ASM, which contains
the QPrint function. The Qprint function returns an integer.

.MODEL MEDIUM, BASIC
.DATA
        shortnum dw 12345

.CODE
        PUBLIC QPrint
QPrint  PROC
        mov ax, shortnum    ; return value in ax register
        ret
QPrint  ENDP
        END

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

   BC IFUNC.BAS;
   MASM AINT.ASM;
   LINK IFUNC AINT;

IFUNC.EXE produces the following output:

   12345
   12345
   12345
   12345
   12345