Group Four

PRESENTATION OF MANAGEMENT INFORMATION SYSTEM PREPARED BY: ARPIT GARG ROHIT BANSAL AMANJOT SINGH SHIVANI RUSTAGI

CONTENTS  CENTRAL

PROCESSING UNIT  ALU V/S CU  COMPUTER MEMORY  VOLATILE AND NON VOLATILE  PRIMARY AND SECONDARY STORAGE  RAM, SRAM AND DRAM  ROM, PROM AND EPROM  PCMCIA CARD

CENTRAL PROCESSING UNIT (CPU) 

The CPU is the brains of the computer. Sometimes referred to simply as the central processor, but more commonly called processor.

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The CPU is where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.

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The CPU itself is an internal component of the computer. Modern CPUs are small and square and contain multiple metallic connectors or pins on the underside. The CPU is inserted directly into a CPU socket, pin side down, on the motherboard. Each motherboard will support only a specific type or range of CPU so you must check the motherboard manufacturer's specifications before attempting to replace or upgrade a CPU. Modern CPUs also have an attached heat sink and small fan that go directly on top of the CPU to help dissipate heat.

MAIN TWO COMPONENTS OF CPU:  The

ARITHMETIC  LOGIC  UNIT (ALU), which performs arithmetic and logical operations.

 The

CONTROL  UNIT (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.

ARITHMETIC LOGIC UNIT (ALU)  

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An arithmetic logic unit (ALU) is a digital circuit that performs arithmetic and logical operations. The ALU is a fundamental building block of the central processing unit (CPU) of a computer, and even the simplest microprocessors contain one for purposes such as maintaining timers. The processors found inside modern CPUs and graphics processing units (GPUs) have inside them very powerful and very complex ALUs;a single component may contain a number of ALUs.

CONTROL UNIT (CU)  The

Control Unit can be thought of as the brain of the CPU itself. It controls based on the instructions it decodes, how other parts of the CPU and in turn, rest of the computer systems should work in order that the instruction gets executed in a correct manner.

There are two types of control units.  The first type is called Hardwired control unit.  The other type of control unit is Micro programmed control unit.

COMPUTER MEMORY  Computer

memory is usually meant to refer to the semiconductor technology that is used to store information in electronic devices.  Current primary computer memory makes use of integrated circuits consisting of silicon-based transistors. There are two main types of memory:  Volatile  Non-volatile

VOLATILE MEMORY    

Volatile memory is computer memory that requires power to maintain the stored information. Current semiconductor volatile memory technology is usually either static RAM or dynamic RAM. Static RAM exhibits data remanence, but is still volatile, since all data is lost when memory is not powered. Dynamic RAM allows data to be leaked and disappear automatically without a refreshing.

Upcoming volatile memory technologies that hope to replace or compete with SRAM and DRAM include Z-RAM and TTRAM.

NON-VOLATILE MEMORY 

Non-volatile memory is computer memory that can retain the stored information even when not powered.

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Examples of non-volatile memory include read-only memory, flash memory, most types of magnetic computer storage devices (e.g. hard disks, floppy disks, and magnetic tape, optical discs, and early computer storage methods such as paper tape and punch cards) Upcoming non-volatile memory technologies include FeRAM, CBRAM, PRAM, SONOS, RRAM, Racetrack memory, NRAM and Millipede.

PRIMARY STORAGE 

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Primary storage, presently known as memory, is the only one directly accessible to the CPU. The CPU continuously reads instructions stored there and executes them as required. Any data actively operated on is also stored there in uniform manner. Historically, early computers used delay lines, Williams tubes, or rotating magnetic drums as primary storage. By 1954, those unreliable methods were mostly replaced by magnetic core memory, which was still rather cumbersome. Undoubtedly, a revolution was started with the invention of a transistor, that soon enabled thenunbelievable miniaturization of electronic memory via solid-state silicon chip technology. This led to a modern random access memory (RAM). It is smallsized, light, but quite expensive at the same time. (The particular types of RAM used for primary storage are also volatile, i.e. they lose the information when not powered).

SECONDARY STORAGE  

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Secondary storage, or storage in popular usage, differs from primary storage in that it is not directly accessible by the CPU. The computer usually uses its input/output channels to access secondary storage and transfers the desired data using intermediate area in primary storage. Secondary storage does not lose the data when the device is powered down—it is non-volatile. In modern computers, hard disks are usually used as secondary storage. The time taken to access a given byte of information stored on a hard disk is typically a few thousandths of a second, or milliseconds. By contrast, the time taken to access a given byte of information stored in random access memory is measured in billionths of a second, or nanoseconds. Some other examples of secondary storage technologies are: flash memory (e.g. USB sticks or keys), floppy disks, magnetic tape, paper tape, punch cards, and Zip drives.

RAM (Random-access memory) 

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RAM is a form of computer data storage. Today it takes the form of integrated circuits that allows the stored data to be accessed in any order (i.e., at random). The word random thus refers to the fact that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data.

DRAM (Dynamic random access memory ) 

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DRAM is a type of random access memory that stores each bit of data in a separate capacitor within an integrated circuit. Since real capacitors leak charge, the information eventually fades unless the capacitor charge is refreshed periodically. Because of this refresh requirement, it is a dynamic memory as opposed to SRAM and other static memory. Advantage DRAM is structurally simple DRAM reach very high density

Image of DRAM

SRAM (Static random access memory )  SRAM

is a type of semiconductor memory.  The word static indicates that, unlike dynamic RAM (DRAM), it does not need to be periodically refreshed, as SRAM uses bistable latching circuitry to store each bit. SRAM exhibits data remanence, but is still volatile in the conventional sense that data is eventually lost when the memory is not powered.  The term SDRAM, which stands for synchronous  DRAM, should not be confused with SRAM.

Image of SRAM

ROM (Read-only memory )  ROM

is a class of storage media used in computers and other electronic devices.  Data stored in ROM cannot be modified (at least not very quickly or easily), it is mainly used to distribute firmware (software that is very closely tied to specific hardware, and unlikely to require frequent updates).  In its strictest sense, ROM refers only to mask ROM (the oldest type of solid state ROM), which is fabricated with the desired data permanently stored in it, and thus can never be modified.

Image of ROM

PROM (programmable read-only memory ) 

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A (PROM) is a form of digital memory where the setting of each bit is locked by a fuse or antifuse. Such PROMs are used to store programs permanently. They are frequently seen in video game consoles, or such products as electronic dictionaries, where PROMs for different languages can be substituted.

EPROM (Erasable Programmable ReadOnly Memory) An EPROM, is a type of memory chip that retains its data when its power supply is switched off.  In other words, it is non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages than those normally used in digital circuits.  Once programmed, an EPROM can be erased only by exposing it to strong ultraviolet light. That UV light usually has a wavelength of 253.7nm (for optimum erasure time) and belongs to the UVC range of UV light.  EPROMs are easily recognizable by the transparent fused quartz window in the top of the package, through which the silicon chip can be seen, and which permits UV light during erasing. 

PCMCIA CARD (Personal Computer 

Memory Card International Association)  

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In computing, PC Card is the form factor of a peripheral interface designed for laptop computers. The PC Card standard (as well as its successor ExpressCard) were defined and developed by a group of industry-leading companies called the Personal Computer Memory Card International Association (PCMCIA). PC Card was originally designed for computer memory expansion, but the existence of a usable general standard for notebook peripherals led to many kinds of devices being made available in this form. Typical devices included network cards, modems, and hard disks. The cards were also used in early digital SLR cameras, such as the Kodak DCS 300 series. The original use, as memory expansion, is no longer common. Many notebooks in the 1990s came with two type-II slots with no barrier in between (allowing installation of two type-II cards or one, double-sized, typeIII card). With the removal of legacy ports, most contemporary notebooks only feature a single type-II card slot, and an increasing number of less expensive notebooks feature no PC Card slot at all.

Images of PCMCIA CARD

REFERENCES    

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