Q57363: How to Pass a Variable Length String from BASIC to MASM

Article: Q57363
Product(s): See article
Version(s): 7.00   | 7.00
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | SR# S891017-100 | mspl13_basic
Last Modified: 17-JAN-1990

The example below demonstrates how to pass a variable-length string
from a compiled BASIC program to a MASM procedure. This information
applies to Microsoft BASIC Professional Development System (PDS)
Version 7.00 for MS-DOS and MS OS/2.

BASIC to MASM Example
---------------------

Compile and link as follows:

Compile: BC /Fs/d basmasm.bas;
         MASM masmtest;
Link:    LINK basmasm+masmtest,,,BRT70EFR;

REM ==BASIC to MASM code===
DEFINT A-Z
DECLARE SUB printmessage (BYVAL segm, BYVAL offs)
CLS
a$ = "Assembly test successful" + "$"
CALL printmessage(SSEG(a$), SADD(a$))
LOCATE 10, 10
PRINT "Back from assembly"
END

;MASM code here
                    .Model    Medium,basic
                    .stack
                    .code
                    public    printmessage
printmessage        proc      uses ds,segm,offs
                    mov       ax,segm
                    mov       ds,ax
                    mov       dx,offs
                    mov       ah,9
                    int       21h
                    ret
printmessage        endp
                    end

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