Quote:
|
Originally Posted by jerrbitt Thanks for all the interesting information. I wish the SbPocket Plus I purchased had some of those features of the other software you mentioned. Is there a chance that a upcoming version of Windows MObile operating system will incorporate some of those features and which ones are likely do you think?
I still don't understand the difference between memory program and memory storage. I did delete some programs -- games--that I was sure were loaded onto my storage card but anyway that process added about 5 MB to both programs and storage. Nice but I sure would like to understand the process.
Again thanks. |
Here's an Article that i found about Memory of Pocket Pc
Memory is one of the basic components of a device called a pocket computer. It makes little difference how fast the processor, how large and colourful the display and how many wireless radio modules a device carries - without memory, it would be dead box of
hardware. Nevertheless, even the less technically savvy users should read this article. A PDA's memory is a place where you keep the most valuable thing - you data. If you do not want to loose them, you should know at least the elementary issues.
As in real life, the
computer memory, too, has to handle three main tasks - otherwise it would be useless. These include the possibility to write information, retain it and recall. All the information is stored in the binary form - as a combination of ones and zeros. There are many different types of memory but all of them are based on the electromagnetic principle (I have never seen a punch-card reader for Pocket PC
Here, we shall discuss only the types of memory used in Pocket PCs.
Even the simplest pocket computer with a
Microsoft operating system integrates several types of memory that differ in purpose and speed. There are two basic types - ROM (read-only memory) and RAM (random-access memory). In addition, almost every device can be extended using a memory card or other memory media e.g. over a USB Host
interface. However, we will stick to internal memory this time.
RAM / SRAM / DRAM / SDRAM
RAM stands for Random Access Memory. Unlike ROM, the RAM memory needs to be powered to retain its contents. Even the shortest blackout wipes out all data irreversibly. There are many types of RAM but we shall focus only on some of them. Depending on whether a memory is static or dynamic, it is called either SRAM or DRAM. SRAM-type memory (Static RAM) retains data as long as it is powered. It is very fast but more sophisticated and therefore more expensive. It is used primarily as cache memory where speed is a crucial factor. On the other hand, DRAM (Dynamic RAM) retains information using electric charge from a capacitor. However, the charge tends to wither even if the memory is powered. In order to prevent complete discharge and subsequent loss of information, it is necessary to refresh memory cells periodically. It is simpler and therefore significantly cheaper, albeit slower than SRAM.
We shall discuss in detail only SDRAM (Synchronous DRAM) which we can find in virtually all Pocket PCs on the market. As you will guess correctly, it is based on the DRAM technology but is much faster than the original SDRAM due to certain enhancements, such as synchronisation with the frequency of the CPU bus. Favourable price makes it the preferred choice and only rarely can we encounter another type of memory in pocket devices.
How does it work?
You now know what types of memory are used in Pocket PCs, let's see how it all actually works and how a Pocket PC uses the memory. PDA beginners will probably be familiar with a desktop PC, so I will try to compare the two worlds.
All Pocket PCs I have ever seen have both RAM and ROM. Apart from some rare exceptions, there are no pocket computers with an integrated hard drive. The task of permanent storage of data even without power is assigned to the ROM. It contains the operating system, without which the device just would not work, as well as basic applications from Microsoft and other software vendors (it is the manufacturer of the device who decides what software you obtain with the device). In some devices, a part of their Flash ROM is accessible o the user as Safe Storage. When you switch the device on for the first time, a series of initial operations and settings will be performed. Besides other things, data that crate a user profile will be copied to the RAM (system registry, document templates, and bonus applications, if available). After you have calibrated the display and tried Tap&Hold, the device is ready to use.
Most Pocket PC first-timers will suffer a shock upon inspecting available memory. They usually believe that when they buy a device with 64 MB of RAM, they will have that amount of memory at their disposal for storing data and applications. In reality, the amount of free memory is significantly smaller for three reasons:
- As I mentioned above, the system may occupy part of the RAM for its own purposes (such as code shadowing etc.), which reduces the original amount (down to the 55 MB).
- Even a completely new device has some data in it (modules for the Today screen, document templates etc.), which eat up several more megs (that's the blue line)
- The rest will be divided (and dynamically allocated) between storage memory and program memory where applications actually run (that's the slider)
Taken from
PDAGold
I hope this answer your Question.
Murduck
