/FHQ29: What does ``Optimize Communications'' in DESQview's setup program do?/FB



The cards that you install in your computer use ``hardware interrupts''
to tell the CPU that the card has or needs data.  The hardware
interrupts are like grade school students raising their hand in class.
When they teacher recongizes a student with his hand up, that student
can ask//answer a question.



Like many teachers, DESQview has a ``teacher's pet.''  This pet is
hardware interrupt 0.  If a bunch of hardware interrupts raise their
hands at the same time, DESQview will always recognize 0 first, then 1,
then 2, and so on.



However, most COM ports use hardware interrupt levels 3 and 4.  So by
answering ``Y'' to ``Optimize Communications'', you force interrupt
level 3 to become the teacher's pet.  DESQview will then recognize the
interrupts in this order: 3, 4, 5, ... 0, 1, 2.  Rather than answering
``Y'', you can put in any interrupt number you prefer.  For example, if
you answer ``5'',  DESQview will recognize the interrupts in the order
5, 6, 7, ... , 0, 1, 2, 3, 4.



Setting ``Optimize Communications'' to ``Y'' can reduce or eliminate
dropped characters in communication programs /JB(see Q25)/q25.txt/.



8086//8088 machines have 8 available hardware interrupts (0-7), while
80286+ machines have 16 (0-15).