Chapter 4 Microprocessor and Memory Concepts Solutions
Question - 21 : - Explain RAM.
Answer - 21 : - Computer RAM is the best known form of memory your computer uses. Every file or application opened is placed in RAM. Any information the computer needs or uses becomes part of a continuous cycle where the CPU requests the data from RAM, processes it and then writes new data back to the RAM. This can happen millions of times a second. However, this is just for temporary file storage, so it is deleted when the files or applications are closed.
Question - 22 : - What do you mean by hard drive ?
Answer - 22 : - A hard drive is a form of computer memory that allows you to permanently store data. This is where all of your permanent files and programs are stored. On computers running with Microsoft windows the hard drive is often called C-drive. The size of a hard drive is typically measured in gigabytes.
Question - 23 : - Explain virtual memory.
Answer - 23 : - Virtual memory typically comes into place when applications are too large for the RAM to handle. The operating system uses the hard drive to temporarily store information and take it back when needed. This is normally a lot slower than actual RAM and can possibly degrade the performance if used too heavily.
Question - 24 : - Where do we use cache memory ?
Answer - 24 : - Cache memory is used in between the CPU and the RAM and holds the most frequently used data or instructions to be processed. There are three different grades of cache.
Question - 25 : - What do you mean by port ? Write its types also.
Answer - 25 : -
A port is a connection point or interface between a computer and internal or external devices.
Some common types of ports are :
1. Serial Port.
2. Parallel Port.
3. USB Port.
4. Bluehx th.
5. PS/2 Port.
6. Infrared Port.
7. Firewire Port.
Question - 26 : - Explain difference between serial and parallel data transfer.
Answer - 26 : - Parallel data transfer refers to the type of data transfer in which a group of bits are transferred simultaneously while serial data transfer refers to the type of data transfer in which a group of data bits are transferred one bit at a time. So that means that the amount of data transferred serially is less than the data transferred parallel per second.
Question - 27 : - What do you mean by PS/2 port ?
Answer - 27 : - A type of port developed by IBM for connecting a mouse or keyboard to a PC. The PS/2 port supports a mini DIN plug containing just 6 pins. Most PCs have a PS/2 port so that the serial port can be used by another device, such as a modem. The PS/2 port is often called the mouse port.
Question - 28 : - Explain 3.5 inch floppy disk.
Answer - 28 : - Micro floppy disks (3.5 inch) if it is high density (MF2HD), can store 1.44 MB and if it is low density (MF2DD), can store 720 KB. Mini Floppy disks (5.25 inch) if it is high density (MD2HD), can store 1.2 MB and low density (MD2DD), stores 360 KB of data.
Question - 29 : - What do you mean by Extended Binary Coded Decimal Interchange Code ?
Answer - 29 : - EBCDIC is an 8-bit binary code for larger IBMs primarily mainframes in which each byte represent one alphanumeric character or two decimal digits. 256 characters can be coded using EBCDIC.
Question - 30 : - Expalin Cache Memory.
Answer - 30 : -
A CPU cache is a cache used by the Central Processing Unit (CPU) of a computer to reduce the average time to access data from the main memory. The cache is a smaller, faster memory which stores copies of the data from frequently used main memory locations. Most CPUs have different independent caches, including instruction and data caches, where the data cache is usually organized as a hierarchy of more cache levels (LI, L2, etc.)
When the processor needs to read from or write to a location in main memory, it first checks whether a copy of that data is in the cache. If so, the processor immediately reads from or writes to the cache, which is much faster than reading from or writing to main memory.
Most modern desktop and server CPUs have at least three independent caches: an instruction cache to speed up executable instruction fetch, a data cache to speed up data fetch and store, and a translation look aside buffer (TLB) used to speed up virtual-to- physical address translation for both executable instructions and data. The data cache is usually organized as a hierarchy of more cache levels.