Did you know that Microsoft® Windows® CE 3.0,
which the Pocket PC uses, supports real-time task switching between
applications? This article explains what real-time multitasking is and
how it improves the Pocket PC.
What Is Real-time Task Switching?
Real-time task switching is loosely defined
as the ability of the operating system to switch tasks in
approximately 50 milliseconds or less. Real time task switching is
normally required by some embedded systems that need real fast
responses to events. The prior release of Windows CE, version 2.11,
switches tasks in about 250 milliseconds. Windows CE 3.0 on the Pocket
PC is much faster, which makes the system run smoother.
How Does the Pocket PC Benefit from Support
of Real Time?
Did you know that your Pocket PC is running
multiple tasks even when just displaying the Today screen? These tasks
are the kernel, shell, and GDI (Graphics Display Interface) -- in
addition to any applications you are using. The Pocket PC is
constantly switching between these tasks, and between other programs
you are running simultaneously. This means that there are many times
while you are using your Pocket PC when it has to switch between
applications, in order for it to finish a function call, a processor
activity. Each time a switch occurs, the amount of time the Pocket PC
takes to switch is about one fifth the amount of time that the
Palm-size PC took.
Windows CE uses preemptive multitasking to
guarantee that all applications will have a percentage of the CPU.
Preemptive multitasking means that Windows CE maintains a list of
tasks that are running and provides a guarantee that those
applications will have a percentage of the CPU. This allows you to run
other applications in the background on your Pocket PC while you run
the application that you are working with.
Applications That Benefit from Real Time
The time savings add up to benefits that
everyone can see. Each time you run an application and switch to
another, the system responds faster than it ever has before. This is
really noticeable in applications that are time sensitive, such as the
Windows® Media Player, which would skip parts of the music if it were
interrupted for a long period of time. With real-time switching, you
can run other programs while playing music. It also allows for faster
and smoother playback of videos on Pocket PCs with video players, such
as the Casio E-115 using the Casio Video Player. Other Pocket PCs are
able to play back MPEG videos using
Pocket TV. You will also notice smoother
game playing in graphics-intensive games as well.
Real-time task switching enhances your
ability to use your Pocket PC by making it faster and more efficient.
This really makes a difference for applications that are very
CPU-intensive -- such as video players,
Primer, games, and Windows Media Player.
This invisible enhancement makes the Pocket PC more enjoyable to use.