Memory Narinder Singh Lecturer Computer Science Department GCG-11, Chandigarh. Memory Types Secondary Memory Primary Memory RAM SRAM DRAM ROM PROM EPROM Hybrid EEPROM.

Title: Computer Memory 1 Computer Memory 2 Computer Memory • When you think about it, it's amazing • how many different types of • electronic memory you encounter in • daily life. • Many of them have become an • integral part of our vocabulary. • RAM ROM Cache Dynamic • RAM Static RAM Flash RAM • BIOS Memory Sticks • Virtual memory Video memory 3 • You already know that the computer in front of you has memory. What you • may not know is that most of the electronic items you use every day have some • form of memory also. Here are just a few examples of the many items that use • memory • Cell phones Game consoles Car radios VCRs TVs. Each of these devices uses • different types of memory in different ways. 4 Memory Basics • Although memory is technically any form of electronic storage, it is used most • often to identify fast, temporary forms of storage.

If your computer's CPU had • to constantly access the hard drive to retrieve every piece of data it needs, it • would operate very slowly. Zoids Saga English Patch. When the information is kept in memory, the CPU • can access it much more quickly.

Most forms of memory are intended to store • data temporarily. 5 (No Transcript) 6 • As you can see in the diagram above, the CPU accesses memory according to a • distinct hierarchy. Whether it comes from permanent storage (the hard drive) • or input (the keyboard), most data goes in random access memory (RAM) first. • The CPU then stores pieces of data it will need to access, often in a cache, and • maintains certain special instructions in the register.

We'll talk about cache and • registers later. Driver Hisense Andromax U2. 7 The PC Process • All of the components in your computer, such as the CPU, the hard drive and • the operating system, work together as a team, and memory is one of the most • essential parts of this team. From the moment you turn your computer on until • the time you shut it down, your CPU is constantly using memory. Let's take a • look at a typical scenario 8 How Computer Memory Works • When you turn the computer on.The computer loads data from read-only • memory (ROM) and performs a power-on self-test (POST) to make sure all the • major components are functioning properly. As part of this test, the memory • controller checks all of the memory addresses with a quick read/write operation • to ensure that there are no errors in the memory chips.

Read/write means that • data is written to a bit and then read from that bit. • The computer loads the basic input/output system (BIOS) from ROM. The • BIOS provides the most basic information about storage devices, boot sequence, • security, Plug and Play (auto device recognition) capability and a few other • items. 9 • The computer loads the operating system (OS) from the hard drive into the • system's RAM. Ccsarp Coding Manual Apologies more.

Generally, the critical parts of the operating system are • maintained in RAM as long as the computer is on. This allows the CPU to have • immediate access to the operating system, which enhances the performance and • functionality of the overall system. • When you open an application, it is loaded into RAM.

To conserve RAM • usage, many applications load only the essential parts of the program initially • and then load other pieces as needed. • After an application is loaded, any files that are opened for use in that • application are loaded into RAM. 10 • When you save a file and close the application, the file is written to the specified • storage device, and then it and the application are purged from RAM. • In the list above, every time something is loaded or opened, it is placed into • RAM. • This simply means that it has been put in the computer's temporary storage • area so that the CPU can access that information more easily. The CPU requests • the data it needs from RAM, processes it and writes new data back to RAM in a • continuous cycle. In most computers, this shuffling of data between the CPU • and RAM happens millions of times every second.