Q49395: Example of Passing Numerics from BASIC to MASM by Value

Article: Q49395
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: 10-AUG-1990

The two programs below demonstrate how a Microsoft BASIC program
passes standard numeric types to assembly language by value.

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 BNUMVAL.BAS, which passes two standard
numeric types to assembly language by value:

   DECLARE SUB ValInt(BYVAL i%)
   DECLARE SUB ValLong(BYVAL l&)
   i% = ASC("A")
   l& = ASC("B") * 65536 + ASC("C")
   CLS
   CALL ValInt(i%)
   CALL ValLong(l&)
   END

The following program is ANUMVAL.ASM, which gets two standard numeric
types by value and prints them out:

; The following handy .MODEL MEDIUM,BASIC directive is found in MASM
; 5.10 but not in earlier versions:
.MODEL MEDIUM, BASIC
.CODE
        PUBLIC ValInt, ValLong
ValInt  PROC
        push bp
        mov bp, sp            ; set stack frame
        mov dx, [bp+6]        ; get integer
        mov ah, 02            ; DOS interrupt to print character
        int 21h
        pop bp
        ret 2
ValInt  ENDP

ValLong PROC
        push bp
        mov bp, sp            ; set stack frame
        mov dx, [bp+6]        ; get first part of long
        mov ah, 02            ; DOS interrupt to print character
        int 21h
        mov dx, [bp+8]        ; get second part of long
        int 21h               ; print it
        pop bp
        ret 4
ValLong ENDP
        END

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

   BC BNUMVAL.BAS;
   MASM ANUMVAL.ASM;
   LINK BNUMVAL ANUMVAL;

BNUMVAL.EXE produces the following output:

   ABC

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