việc với bất kỳ tập tin flv nào mà bạn tải về từ bất kỳ dịch vụ chia sẻ video nào chứ không chỉ YouTube. Hồng Anh PC World Mỹ 12/2006 Làm vệ sinh cho các thanh RAM và Card (Dân trí) - Các thanh RAM và card chức năng (card màn hình, card sound, modem…) lâu ngày sử dụng sẽ bám bụi, nhất là những khe cắm AGP hay PCI trên mainboard. Bài viết sẽ hướng dẫn cách làm vệ sinh cho chúng. Có thể dùng cọ quét sơn loại nhỏ hay ống xịt bụi làm sạch bụi bẩn, nhưng riêng đầu cắm (có những chân cắm màu vàng) thì có thể xảy ra hiện tư ợng hoen ố do bụi bám lâu ngày gây nên. Để làm được việc này thật đơn giản và hiệu quả giúp cho những card của chúng ta luôn mạnh khỏe và bền bạn chỉ cần làm các bước sau: - Một cục tẩy bút chì (không dùng tẩy bút mực), khăn giấy. - Tắt nguồn, chờ 15 phút và tháo các card chức năng. - Lấy cục tẩy chà đi chà lại 4-5 lần theo chiều dọc vào các chân cắm màu vàng, dùng khăn giấy phủi nhẹ, rồi tiếp tục chà, đến khi nào bạn cảm thấy sáng sủa, hết bụi, vết hoen ố mờ hẳn thì thôi. - Dùng ống xịt bụi hay cọ quét sơn quét lại bụi, làm sạch bụi ở các khe cắm card trên mainboard. Xong việc bạn có thể cắm lại vào máy và vận hành tiếp. Hoa Đào Computer system Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m Computer System Book I: computer system fundamentals. Chapter 1: INTRODUCTION TO COMPUTER. Question 1. What is a computer? A computer may be defined as a machine which accepts data from an input device, processes it by performing arithmetical and logic operations in accordance with a program of instructions and returns the results through an output unit. A computer is basically an electronic machine operating on current. Question 2. Components of a Computer system? A computer system comprises of the following components: 1. Central Processing Unit (CPU). - CPU is the heart of the whole sys - CPU consists of the : control unit (CU) arithmetic logic unit (ALU) accumulator (ACC) Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m program counter (PC) instruction register (IR) memory address register (MAR) memory data register (MDR) status register (SR) general purpose register - The function of each components of CPU: Control unit: control and co_ordinate all hardware functions of the CS. examine and decode all program instructions to the computer and initiate their execution by sending the appropriate signals. ALU: performs all arithmetic <addition, subtraction, multiplication, division & exponentiation> and logic comparision two values functions required by computer. ACC: holds the first operand of the temporary result of the ALU. PC: contains the add of the next instruction to be excuted. IR: contains the current instruction to be executed. Main memory MAR: holds the address location to or from which data is to be transferred MDR: contains the data to be written to or read out of the addressed location. SR: keeps track of the status of the accumalator. General Purpose Register: for general purpose procedures. Please refer to diagram for an illustratin of the basic components of the CPU. Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m I N T E R N A L CPU Control unit Arithmetic Logic Unit Accumulator Program Couter to main Instruction Register memory Memory Address Register Memory Data Register Status Register General Purpose Register Basic components of a CPU. Control Unit Input Unit ALU Output Unit Main Memory Backing Storage Control signals Data flow Components of a CS. 2. Input units - Used to enter data( raw unprocessed facts) and instructions to the computer. 3. Output units - Used for delevering the processed result from the computer in useful form. 4. Backing storage units - Backing storage units need for high capacity data storage devices that can store data in a more permanent form for later retrieral, updating and referencing. - Backing storage is also called secondary storage external storage and auxiliary storage. B U S Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m Chapter 2: MICOPROCESSOR. Question 1. Cache Memory? - Cache memory is a small amount of very fast store with faster access time than the main memory. - Cache memory is used to temporaryty store data instructions that are likely to be retrieved many times, thus speeds up the processing of data. - Sits between main storage and the processor acting as holding area through which all data and instructions pass. - Old data in the cache memory is over written by new then cache is full. Question 2. Virtual Memory? - Virtual memory makes use of both the main memory and backing store. - In a virtual memory sys, each user has the illusion that his program is in the main memory all the time. - The sys maintains this illusion by keeping some of the “unused” portion of the program’s code and data on a backing store device which is usually magnetic disk - The movement of the unused portion from the backing store to the mian memory is transparent to the users. - Please refer to diagram for virtual memory. Backing Store Main Memory Virtual Memory Chapter 3: BATCH/ ONLINE AND REAL TIME PROCESSING SYSTEM. Question 1. Batch Processing System? - Def: Computer processing does not begin until all the input data has been collected and grouped together called Batched Generally data is accumulated for a certain period of time or unitl a certain quantity. - Ads: Response time is not critical. Need to process large volumn of data. Computer efficiency is more important than response time. - Dis: Time between recording and processing of source document is long A3 A1 A2 A2 A3 A1 Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m Click to buy NOW! P D F - X C h a n g e V i e w e r w w w . d o c u - t r a c k . c o m . the main memory and backing store. - In a virtual memory sys, each user has the illusion that his program is in the main memory all the time. - The sys maintains this illusion by keeping some. Backing Store Main Memory Virtual Memory Chapter 3: BATCH/ ONLINE AND REAL TIME PROCESSING SYSTEM. Question 1. Batch Processing System? - Def: Computer processing. unit: control and co_ordinate all hardware functions of the CS. examine and decode all program instructions to the computer and initiate their execution by sending the appropriate signals.