Article: Q64107
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | H_MASM S_QUICKASM B_BasicCom SR# S900718-40 | mspl13_basic
Last Modified: 13-AUG-1990
The two programs shown below demonstrate how an assembly language
function can return a double-precision number 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 for the following
word:
BAS2MASM
Code Example
------------
The following BASIC program is DFUNC.BAS, which displays a
double-precision number returned from an assembly language function:
DECLARE FUNCTION QPrint#
FOR i% = 1 to 2
PRINT QPrint#
NEXT
The following program is ADBL.ASM, which will return a
double-precision number when called:
; The following handy .MODEL MEDIUM,BASIC directive is found in MASM
; 5.10 but not in earlier versions:
.MODEL MEDIUM, BASIC
.DATA
doublenum dq 6765.89
.CODE
PUBLIC QPrint
QPrint PROC
mov bp, sp
push es
push si
push di
push ds ; set es = ds
pop es
mov si, offset dgroup:doublenum
mov di, [bp+6] ; load value into address at bp+6
mov cx, 4
rep movsw ; 4 words at 2 bytes = 8 bytes
mov ax, [bp+6] ; load offset of temp value in ax and
mov dx, ss ; ss into dx
pop di
pop si
pop es
pop bp
ret 2
QPrint ENDP
END
To demonstrate these programs from an .EXE program, compile and link
as follows:
BC DFUNC.BAS;
MASM ADBL.ASM;
LINK DFUNC ADBL;
DFUNC.EXE produces the following output:
6765.89
6765.89