Microsoft KB Archive/49388

= Example of Passing Fixed-Length String Between Basic and MASM =

Article ID: 49388

Article Last Modified on 11/21/2006

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APPLIES TO


 * Microsoft QuickBasic 4.0
 * Microsoft QuickBASIC 4.0b
 * Microsoft QuickBasic 4.5 for MS-DOS
 * Microsoft BASIC Compiler 6.0
 * Microsoft BASIC Compiler 6.0b
 * Microsoft BASIC Professional Development System 7.0
 * Microsoft BASIC Professional Development System 7.1

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This article was previously published under Q49388



SUMMARY
The two programs below demonstrate how Microsoft Basic and assembly language pass fixed-length strings by near reference.

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.



MORE INFORMATION
For more information about passing other types of parameters between Basic and MASM, search in the Microsoft Knowledge Base using the following word:

BAS2MASM

Code Example
The following Basic program is BFSTRN.BAS, which creates a fixed-length string that is passed to assembly language to print and receives a fixed-length string from assembly: DECLARE SUB RString(BYVAL offs AS INTEGER) TYPE fixstring s AS STRING * 20 END TYPE DIM a AS STRING * 20 CLS a = &quot;Basic String$&quot;     ' &quot;$&quot; terminates string for assembly CALL RString(VARPTR(a)) END SUB BasicSub(a AS fixstring) LOCATE 2, 1   ' Must LOCATE because print in assembly won't move PRINT a.s     '   Basic's screen position END SUB The following program is AFSTRN.ASM, which gets a fixed-length string by near reference, prints the string, then passes a string to a Basic subprogram: ; The following handy .MODEL directive is found in MASM 5.10 but not .MODEL MEDIUM, Basic EXTRN BasicSub:PROC .DATA astr DB 'Assembly String      '
 * in earlier versions:

.CODE

PUBLIC RString RString PROC push bp       mov bp, sp           ; set stack frame mov dx, [bp+6]      ; address of string mov ah, 9           ; DOS interrupt to print string int 21h

mov ax, OFFSET astr ; address of assembly string push ax             ; pass it to Basic call BasicSub

pop bp       ret 2 RString ENDP

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

BC BFSTRN.BAS;

MASM AFSTRN.ASM;

LINK BFSTRN AFSTRN;

BFSTRN.EXE produces the following output:

Basic String

Assembly String

Additional query words: QuickBas BasicCom

Keywords: KB49388

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