Multi-Tasker Detection Routines
                             by David Gibbs
                          FidoNet: 1:115/439.0
             Internet: David.Gibbs@f439.n115.z1.fidonet.org

The following is a set of C routines that will enable a programmer to
detect a mutli-tasking environment and release the time slice when
desired.  Currently DESQview, Windows, & OS/2 are the environments
supported.

Routines consist of two functions, two global int variables, one global
structure, and a table of character pointers.

void t_get_os(); This routines detects the operating environment, sets
on the appropriate bits in the t_os_type field, and sets the t_os field
to the dominant environment.

void t_slice(); This routine will release the remainder of the current
tasks time slice in the manner appropriate to the dominant envionment.

The following fields & structures are available...

int t_os_type; is a bit mapped integer that indicates the presence of
various operating envionments.  If Bit 0 is on, DOS is present, Bit 1 =
OS2, bit 2 = DESQview, bit 3 = Windows standard, bit 4 = Windows 386
Enh.  These bits can be tested by using logical operations with the
symbolic constants is_DOS, is_OS2, is_DV, is_WINS, and is_WIN3.

int t_os; represents the dominant environment.  The dominant envionment
is defined as the multi-tasking system that takes precidence.  For
instance, you can run Windows *UNDER* DESQview, but DESQview would be
dominant, the same goes true for OS/2 & Windows.  This value can be
tested by comparing to the symbolic constants: DOS, OS2, DV, WINS, and
WIN3.

struct t_os_ver ts_os_ver[]; indicates the versions of the various
environments present.  Major & minor versions are found in the
structure members 'maj' and 'min'.  The structure is subscripted, so you
can access the version of envionments using the symbolic constants use
in 't_os'.

const char *t_os_name[]; contains the names of the environments
detectable.  These too are subscripted and can be accessed using the
symbolic constants above.

A sample program that uses these routines follows:

#include <stdio.h>
#include "tasker.h"

void main() {
        get_os();

        printf("%s %d.%d detected",t_os_name[t_os],
                                   t_os_ver[t_os].maj,
                                   t_os_ver[t_os].min);

        while(!kbhit()) {
                printf("Hit a key!\r\n");
                t_slice();
        }
}


Special thanks go to Geoffery Booher (1:2270/233) for assistance with
Windows & OS/2 detection & Time slicing.

This routine is released to the public as CommentWare - If you use it,
please send me a comment as to what you thought of it... oh yeah, you
might think of giving me credit for the routines.

Also, if you can think of a enhancement or correction, please let me
know.  I can be reached at the above mentioned email addresses.

Copyrights: DESQview by Quarterdeck Office Systems
            Windows by Microsoft
            OS/2 by IBM
            TurboC++ by Borland