by Dinesh Thakur Category: Memory

Primary memory is also known as main memory or may also refer to "Internal memory." and primary storage. All those types of computer memories that are directly accessed by the processor using data bus are called primary memory. That allows a processor to access stores running programs and currently processed data that stored in a memory location.



 
by Dinesh Thakur Category: Memory

Definition: Flash memory (Known as Flash Storage) is a type of non-volatile storage memory that can be written or programmed in units called “Sector” or a “Block.” Flash Memory is EEPROM (Electronically Erasable Programmable Read-Only Memory) means that it can retain its contents when the power supply removed, but whose contents can be quickly erased and rewritten at the byte level by applying a short pulse of higher voltage. This is called flash erasure, hence the name. Flash memory is currently both too expensive and too slow to serve as main memory.

 
by Dinesh Thakur Category: Memory

A computer device, such as a CD-ROM drive or printer, which is not part of the essential computer, i.e., the memory and microprocessor. Peripheral devices can be external -- such as a mouse, keyboard, printer, monitor, external Zip drive or scanner -- or internal, such as a CD-ROM drive, CD-R drive or internal modem. Internal peripheral devices are often referred to as integrated peripherals. Linkage between the CPU and the users is provided by Peripheral devices.



 
by Dinesh Thakur Category: Memory

Optical Mark Recognition (OMR) is the technology of electronically extracting intended data from marked fields, such as checkboxes and fill-in fields, on printed forms. It is generally distinguished from OCR by the fact that a recognition engine is not required. This requires the image to have high contrast and an easily-recognizable or irrelevant shape.



 
by Dinesh Thakur Category: Memory

OCR stands for optical character recognition, a wonderful and marvellous technology. It enables you to convert previously printed text material into information your computer can understand, without having to retype it. Have you ever had a story or an article or a magazine clipping that you wanted to have in your computer, but the thought of retyping the entire thing was overwhelming? Or just boring? That's what OCR is for.



 
by Dinesh Thakur Category: Memory

Bubble memory is a type of non-volatile computer memory that uses a thin film of a magnetic material to hold small magnetized areas, known as bubbles or domains, each storing one bit of data. Andrew Bobeck invented the Bubble Memory in 1970. His development of the magnetic core memory and the development of the twistor memory put him in a good position for the development of Bubble Memory.



 
by Dinesh Thakur Category: Memory

There are two types of relational integrity rules

Entity Integrity: - No attribute participating in the primary key of a base relation allowed containing any nulls. Primary key performs the unique identification function in a relational model. Thus a null primary key value within a base relation would be like saying that there was some entity that had no known identity. An entity that cannot be identified is a contradiction in terms, hence the name entity integrity.

 
by Dinesh Thakur Category: Memory

Definition: EPROM (pronounced ee-prom ) stands for Erasable Programmable Read-Only Memory. EPROM is a type of ROM chip that can retain the data even if there is no power supply. The data can be erased and reprogrammed by using ultraviolet (UV) light. The UV light clears the data on the chip so that it can reprogram. For writing and erasing data on the EPROM, we need a particular device which is known as PROM programmer. The process of programming an EPROM is often called BURNING, and the box into which it is plugged to program it an EPROM burner.

 
by Dinesh Thakur Category: Memory

Hard Disk Access time is the total elapsed time between the initiation of a particular request for data and receipt of the first bit of that data.

Direct access devices (Hard Disk Drive) require varying times to position a disk head over a particular record. In the case of a moving-head disk drive, this involves positioning the comb (head assembly, as in Fig.) to the designated cylinder, plus rotation of the selected track to the desired record. Comb-movement times for a typical medium-sized disk drive are shown in Fig.



 
by Dinesh Thakur Category: Memory

DDRAM: - Short for Double Data Rate-Synchronous DRAM, a type of SDRAM that supports data transfers on both edges of each clock cycle (the rising and falling edges), effectively doubling the memory chip's data throughput. DDR-SDRAM also consumes less power, which makes it well suited to notebook computers. DDR-SDRAM is also called SDRAM II And DDRAM.

 
by Dinesh Thakur Category: Memory

Definition: DRAM stands for Dynamic Random Access Memory. DRAM is a technical term for a type of random access memory (RAM) that can retain its contents only for a very brief period (measured in milliseconds) and must, therefore, be continually refreshed by reading its contents at short intervals.

 
by Dinesh Thakur Category: Memory

Definition of parity memory: Some Random Access Memory (RAM) chips have built-in error-checking functions that use a process called parity. Chips that use parity have an extra bit for every eight bits of data. In the parity process, as the eight bits receive binary data (data represented by 1s and 0s), the chip adds all the 1s, and if that total is odd, the extra bit is set to 1.The most common data error-checking and validation technique is the Vertical Redundancy Check (VRC) often called a parity check.

 
by Dinesh Thakur Category: Memory

Definition: A buffer is Like a cache, that is a data area of computer memory (RAM) reserved for temporary storage. For instance, you've probably noticed that you can quickly type a bunch of commands on the keyboard, and then just sit back and watch your computer carry out the commands one after another. This is because the computer stores the keys you pressed in a buffer-after doing one command; it goes back to the buffer to get the next one in line.



 
by Dinesh Thakur Category: Memory

Secondary memory is also known as secondary storage. The secondary memory is accessed indirectly via input/output operations. This memory is also called permanent, external, stable or persistent memory. It is characterised by its slowness and cheapness, relative to the RAM, and by its permanent appearance.

 
by Dinesh Thakur Category: Memory

In humans, the memory is mind warehouse , where are stored for a later use the various components experience. The memory of a computer somewhat similar but more limited at its possibilities.



 
by Dinesh Thakur Category: Memory

Associative Cache: A type of CACHE designed to solve the problem of cache CONTENTION that plagues the DIRECT MAPPED CACHE. In a fully associative cache, a data block from any memory address may be stored into any CACHE LINE, and the whole address is used as the cache TAG: hence, when looking for a match, all the tags must be compared simultaneously with any requested address, which demands expensive extra hardware. However, contention is avoided completely, as no block need ever be flushed unless the whole cache is full, and then the least recently used may be chosen.

 
by Dinesh Thakur Category: Memory

Definition: A disk cache (cache memory) is a temporary holding area in the hard disk or random access memory (RAM) where the computer stores information that used repeatedly. The computer can use it to speed up the process of storing and accessing the information much more quickly from the disk cache than if the information stored in the usual place (which might be on a disk or in a part of the computer's memory that takes longer to access). The term disk cache can also refer to a disk buffer and cache buffer.



 
by Dinesh Thakur Category: Memory

Definition: A laser printer (also known as Page Printers as they prints the whole page at once) represent a real technological revolution. laser printer is a type of printer which makes use of a laser beam to produce an image on the drum or you can say that it is a printer that makes use of a focused beam of light to transfer text and images onto paper. It was first developed by Gary Starkweather at Xerox PARC in 1971. Laser printer makes use of laser technology for the printing of copies onto the paper.

The first relatively affordable laser printers were the Apple LaserWriter and the Hewlett-Packard LaserJet. Prices have dropped like a rock and quality is way up since those machines came out, but the underlying technology remains the same.



 
by Dinesh Thakur Category: Memory

The cycle time of a computer is the time required to change the information in a set of registers. This is also sometimes called the state transition time. The register cycle time of a processor is sometimes referred to as the internal cycle time, clock time, or simply cycle time. Main memory cycle time is usually several times the internal cycle time. The internal cycle time may not be of constant value.



 
by Dinesh Thakur Category: Memory

The disk controller is circuitry on the computer's motherboard or on a plug-in circuit board that controls the operation of your hard disk drive, floppy disk drives, or both. When the computer wants to transfer data to or from the disk, it tells the disk controller. The controller in turn sends electronic commands to the disk drive making the disk spin and move its magnetic heads to the proper location on the disk. The controller then transfers the data between the computer and the disk drive. The computer's OPERATING SYSTEM and BIOS issue commands directly to the controller to BOOT the computer and to access files stored on the disks. 



 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.