On May 13 05:02, 1997, andrew clarke of 3:635/728.4{at}fidonet wrote:

ac> 07 May 97 17:34, Matthew Parker (3:712/610.31) wrote to andrew clarke:

>>>> Therefore neither dos version will release time slices
when run under
>>>> windows.

ac>>> Well, not exactly.  dospause() will be called instead, which in
ac>>> turn calls INT 28h.

>> Thats what I originally thought too, but if you look in an interrupt 
>> list it shows only dos and os/2 as supporting it.

ac> That's interesting.  I wonder why Windows doesn't support it?  Actually, I 

 I don't have a clue why windows doesn't support it as a time release
function. But it still supports its use as a way of letting TSR's know
its okay to enter DOS.

ac> also wonder what purpose INT 28h serves when called from outside a 
ac> multitasker (ie. vanilla DOS)...  ?

 TSR's hook it and know they can activate and call DOS. For instance I often
run Norton Diskcache with delay writes enabled with buffers of 3MB. If I
use squish and then enter msged ncache uses each int 28h call for writing
some of the data back to the disk.

Matthew

--- Msged 4.20 beta 1