how pda works
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1. Introduction to How PDAs Work
2. Types of PDAs
3. What PDAs Do
4. The PDA Computer
5. PDA Parts
6. Buying a PDA
7. PDA FAQ
8. Lots More Information
9. See all Notifications articles
The PDA Computer
Microprocessors and Memory
Like standard desktop and laptop computers, PDAs are powered by
microprocessors. The microprocessor is the brain of the PDA, and it
coordinates all of the PDA's functions according to programmed
instructions. Unlike desktop PCs and laptops, PDAs use smaller,
cheaper microprocessors. Although these microprocessors tend to be
slower than their PC counterparts, they are adequate for the tasks
that PDAs perform. The benefits of small size and price outweigh the
cost of slow speeds.
The parts that can make up a PDA
A PDA doesn't have a hard disk. 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.
Your data and any programs you add later are stored in the device's
random-access memory (RAM). Information in RAM is only available when
the device is on. Due to their design, PDAs keep data in RAM safe
because they continue to draw a small amount of power from the
batteries even when you turn the device off.
Less powerful PDAs have lower amounts of RAM. However, many
application programs take up significant memory space, so most models
have more memory. Also, Pocket PC devices generally require more
resources and have even more RAM. To provide additional memory, many
PDAs accept removable flash media add-on cards. These are handy for
storing large files or multimedia content, such as digital photos.
Some newer PDAs, such as the Palm Tungsten E2, use flash memory
instead of RAM. Flash memory is non-volatile, which means it preserves
the data and applications it stores -- even when all battery power is
depleted.
Operating Systems
The operating system contains the pre-programmed instructions that
tell the microprocessor what to do. The operating systems used by PDAs
are not as complex as those used by PCs. They have fewer instructions,
which require less memory.
Here is an inside view of a PDA. The circuit board folds away from the
screen. In the middle of the single-layer circuit board is the
microprocessor, and to the left and above are the memory chips.
PDAs and smartphones typically have one of two types of operating
systems: Palm OS or Windows Mobile. However, RIM makes a specific OS
for its BlackBerry devices, and the Symbian OS operates some
smartphones.
In the next section, we'll look at the other parts that make up a PDA.
