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Working
of a PDA
Regardless
of the type of PDA, they all share the same major
features:
Microprocessors
Like
standard desktop and laptop computers, PDAs are powered by
microprocessors. The microprocessor is the brain of the
PDA and coordinates all of the PDA's functions according
to programmed instructions.
The
Operating system
The
operating system contains the pre-programmed instructions
that tell the microprocessor what to do.
Memory
A PDA doesn't have a hard drive. It stores basic programs
(address book, calendar, memo pad and operating system) in
a read-only memory (ROM) chip, which remains intact even
when the machine shuts down. The data and any programs
that are added later are stored in the device's RAM. This
approach has several advantages over standard PCs.
When the
PDA is turned on , all the programs are instantly
available. One does not have to wait for applications to
load. When changes are made to a file, they're stored
automatically, hence a Save command is not required. And
when the device is turned off, the data is still safe,
because the PDA continues to draw a small amount of power
from the batteries. PDAs usually come with 2 MB minimum of
memory. However, many application programs take up memory
space, so more advanced models usually have more memory (5
to 32 MB). Also, Pocket PC takes more memory space so PDAs
with this operating system usually have 16 or 32 MB. In
some PDA models, the amount of memory is upgradeable.
Batteries
PDAs are powered by batteries. Some models use alkaline
(AAA) batteries, while others use rechargeable batteries
(lithium, nickel-cadmium or nickel-metal hydride). The
battery life depends on what kind of PDA one has and what
it is used for.
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