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Q61675: SSEGADD Example Requires Large Model (/AL) for C Routine

Article: Q61675
Product(s): See article
Version(s): 7.00   | 7.00
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | SR# S900501-79 docerr S_C S_QuickC | mspl13_basic
Last Modified: 11-MAY-1990

The SSEGADD example on Page 351 of the "Microsoft BASIC 7.0: Language
Reference" manual requires that the C routine (printmessage) be
compiled with the large memory model (/AL). The following compile
lines should be added for the C routine:

   For C 5.00 and 5.10
   -------------------

     CL -AL printmsg.c ;

   For QuickC 1.00, 1.01, 2.00, and 2.01
   -------------------------------------

     QCL -AL printmsg.c ;

This information applies to Microsoft BASIC Professional Development
System (PDS) version 7.00.

In general, routines written in C (or other languages) need to be
compiled either for the medium memory (/AM) or the large memory (/AL)
model. The model size affects the default pointer type (near or far).

When the SSEGADD example is compiled for medium model, the program
runs without error, but the wrong data is displayed. This is because
the printf() function is expecting a near pointer (offset in the data
segment) and printmessage is accepting a far pointer (segment and
offset). If you use the large memory model, printf() expects a far
pointer, and the program runs correctly.

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