all of sani

Handheld systems include personal digital assitants (PDAs) such as palm pilots or cellular telephones with connectivity to a network such as the Internet. devlopers of handheld systems and applications face many challanges, most of which are due to the limited size of such devices. for example, a PDA is typically about 5 inches in height and 3inches in width, and it weighs less than one-half pound due to this limited size, most handheld devices have a small amount to memory, include slow processors, and features small disply screens. We will take a look now at each of these limitation.
Many handheld devices have between 512KB and 8MB of memory. (Contrast this with a typical PC or workstation, which may have servel hundred megabytes of memory!) As a result, the operating system and applications must manage memory efficiantly. this includes returning all allocated memory back to the memory manager once the memory is no longer being used. virtul memory which allows devlopers to write programms that behave as if the system has more memory, than may be physically avilable. forecing program devlopers to work within the confines of limited physical memory.
A second issue of concern to developers of handheld devices is the speed of the processor used in the device. Processor for most handheld devices often run at a fraction of the speed of a processor in a PC. Faster Processors require more power. To include a faster processor in a handheld device would require a larger battery that would have to be replaced (or recharged) more frequently. To minimize the size most handheld devices, smaller, slower processor which consume less power are typically used. Therefore, the operating system and application must be designed not to tax the processor
Some handheld devices may use wireless technology, such as Bluetooth allowing remote acess to e-mail and web browsing cellular telephones with connectivity to the internet fall into this catagory. However,many PDAs currently do not provide wireless access To download data to these devices, typically one first downloads the data to a PC or workstation, and then downloads the data to the PDA. Some PDAs allow data to be directly copied from one device to another using an infraed link