Computer Programming

Originally the term referred to people who used a razor blade and/or fingernail clippers to "hack" or roughly cut parts in electronics such as the traces on circuit boards, legs of diodes etc. Police scanners were "hacked" in order to add more memory, remove CPU processors , speed up scanning by "hacking" the crystal oscillator and replacing with faster ones. Thes methods are directly related to why computers now have more RAM, and are faster. Some of the old (and I do mean old) "hackers" devised a system in the 1960s to simultaneously send voice and data over a phone line using frequency phase shifting and filtering. A similar process used later by DSL.

"Hacking" and "Modding" evolved into things such as examining the programming of a thing. Beginning with noticing things such that by pressing certain keys or combinations of keys in certain secquences on a device could produce certain results. Following the era of IBM's "Big Blue" chess tournament, AT&T introduced the "unbeatable Tic Tac Toe Computer, and exhibited it. I, I mean a "hacker" back then, was able to beat the computer with a sequence of key presses in order to "cheat" the computer out of a move. On many Shortwave radios, Police Scanners, even cell phones etc, certain key presses are used in the programming, and could be used to alter that programming.

The keys on a keyboard of a device are a "Matrix" Keyboards use a matrix with the rows and columns made up of wires. Each key acts like a switch. When a key is pressed, a column wire makes contact with a row wire and completes a circuit. The keyboard controller detects this closed circuit and registers it as a key press to the software.

I'm going to try to keep this understandable to readers ...

Software can emulate or act like hardware.

Example: a hardware modem versus a DSP/Digital Signal Processor modem, where a chip is programmed to act like the hardware....

So, later, the focus turned even more from "hacking" the actual electronics and hardware to software "hacking" through PROGRAMMING.

A "black hat" hacker is often referred to as a microcomputer user who attempts to gain unauthorized access to proprietary computer systems. Although that could be a "cracker" ... a person cracking passwords etc.

Most often people who call themselves "hackers" are called "wannabes" by the old-timers, and nowadays are often adolescents using a program they didn't write, by clicking a button they didn't create, to do what don't understand, in an attempt to disrupt something they don't know how to fix.

"White Hat" hackers are the "good guys" like ... Like the old-timers who vastly improved what computers are capable of doing, and the ones currently trying to improve security by locating and preventing weaknesses.

This Answer is dedicated to the memory of Bill Cheek, author, The Scanner Modification Handbook series, and his BBS and Fidonet terminal (prior to "The Internet") Good man, Good freind to many... May he R.I.P.

Structured programming (sometimes known as modular programming) is a subset of procedural programming that enforces a logical structure on the program being written to make it more efficient and easier to understand and modify.

ref:structured programming

Hope this will help u.!!! :)

stucured language mean dividing program in to blocks or parts and executing where one block differs from other so that thr reader can understand the program easy.its just like top-down design approach

The most widely used symbols are:

1. Start and end

2. Arrows

3. Processing steps

3. Conditional Other symbols are:

4. document symbol

5. Manual Operation

6. Data file

= What is information processing cycle? = In: Computer Terminology [Edit categories]

[Edit]

Information processing cycle of computer can be well described by the following points: (1) input, (2) processing, (3) output and (4) storage # Input-entering data into the computer. # Processing-performing operations on the data. # Output-presenting the results. # Storage-saving data, programs, or output for future use.

1. INPUTThe collection of raw data from the outside world so it can be put into an information system. Putting the acquired data into the information system. # Examples: The payroll clerk collects workers' timecards so she knows how many hours each person worked that week and types the hours from the timecards into a spreadsheet # Conducting a survey of customer's opinions and then scanning the survey cards with a card reader. # Collecting jokes for a joke book and typing jokes into a word processor. # Using a form on a website to collect visitors' opinions

Typical input devices: Keyboards, mice, flatbed scanners, bar code readers, joysticks, digital data tablets (for graphic drawing), electronic cash registers

2. PROCESSING CPU Processor - Central ProcessingUnit A central processing unit (CPU), or sometimes simply processor, is the key component in a digital computer capable of executing a program. It interprets computer program instructions and processes data. CPUs provide the fundamental digital computer trait of programmability, and are one of the necessary components found in computers of any era, along with memory and input/output facilities. A CPU that is manufactured as a single integrated circuit is usually known as a microprocessor. Beginning in the mid-1970s, microprocessors of ever-increasing complexity and power gradually supplanted other designs, and today the term "CPU" is usually applied to some type of microprocessor. Microprocessor (CPU)

Integrated circuit, also called a chip. The Brain of the computer

Composed of: ALU: Arithmetic Logic Unit: Processor Controller High speed calculator

Intel is the most popular chip

Categorized by model numbers

Higher model number=newer/faster chip

Speed of CPU is determined by clock speed

Higher the clock speed, faster the computer

Speed is measured in megahertz (MHz) Megahertz: Clock Speed of the processor (100 MHz = 100 million cycles/second). Memory or RAM Next most critical element of a processing hardware is RAM, often referred to as "primary storage" or "main memory". Random Access Memory (RAM) receives and temporarily stores data and program instructions from the CPU This data bank communicates with the CPU, constantly exchanging information and constantly changing as long as the computer is on

RAM is an active, electronic state. When the power is on, RAM retains data. When the computer is turned off, all data in RAM is erased unless you have saved it to some mass storage device. Each time the computer boots, the computer goes through it's startup routine and lastly loads operating system instructions into RAM

Random Access Memory (RAM) is the workhorse behind the performance of your computer. Working as a foot soldier for your processor, RAM temporarily stores information from your operating system, applications, and data in current use. This gives your processor easy access to the critical information that makes your programs run. The amount of RAM you have determines how many programs can be executed at one time and how much data can be readily available to a program. It also determines how quickly your applications perform and how many applications you can easily toggle between at one time. Simply put, the more RAM you have, the more programs you can run smoothly and simultaneously. To determine how much RAM you need, factor in the demands of the applications you want to run simultaneously as well as the operating system (512 MB of RAM is recommended by Microsoft as minimum for operation of Windows) Then keep in mind that you'll inevitably add new applications and create new files, and add accordingly. RAM: (Random Access Memory): (Click here to read "How Stuff Works - RAM") Types of RAM * DRAM (Dynamic RAM) This is the most common type of computer memory. DRAM needs refreshing and is refreshed hundreds of times each second in order to retain data. During recharging it cannot be accessed by the CPS * SRAM (Static RAM) SRAM is approximately 5 times faster (and twice as expensive, as DRAM). It does not have to be constantly refreshed. Because of its lower cost and smaller size, DRAM is preferred for the main memory, while SRAM is used primarily for cache memory. * SDRAM (synchronous dynamic RAM) is the standard memory offering in the PC industry and is faster than DRAM because it's synchronized to the system clock. . It is designed for mainstream home and business applications, email, and basic audio and video streaming. It provides single-channel memory and is available on our mainstream and value desktop system. * DDR SDRAM (double data rate synchronous dynamic RAM) takes all the features of ordinary SDRAM and increases the frequency bandwidth to improve system performance and speed. * RDRAM (Rambus dynamic RAM) is able to load a new stream of data before the previous stream has completed, resulting in faster access speeds. The RDRAM memory features dual-channel processing which doubles data throughput to further enhance performance. This type of memory is optimized for high-end multimedia tasks involving video and audio. Dual Channel RDRAM is shipped on our performance desktop systems powered by Pentium 4 processors * VRAM: Memory designed for storing the image to be displayed. * CACHE RAM is a small block of high-speed memory located between the Processor and main memory and is used to store frequently requested data and instructions. When the processor requests data, it will check in the cache first

Understanding the relationship between CPU and RAM The hierarchical arrangement of memory storage in current computer architectures is called the memory hierarchy. It is designed to take advantage of memory locality in computer programs. Each level of the hierarchy is of higher speed and lower latency, and is of smaller size, than lower levels. The memory hierarchy in most computers is as follows: * Processor registers - fastest possible access (usually 1 CPU cycle), only hundreds of bytes in size * Level 1 (L1) cache - often accessed in just a few cycles, usually tens of kilobytes * Level 2 (L2) cache - higher latency than L1 by 2× to 10×, often 512 KiB or more * Level 3 (L3) cache - higher latency than L2, often several MB * Main memory (DRAM) - may take hundreds of cycles, but can be multiple gigabytes. Access times may not be uniform.

3. Output In information processing, output is the process of transmitting the processing information Essentially, output is the presentation of any data exiting a computer system. This could be in the form of printed paper, audio, video. In the medical industry this might include CT scans or x-rays. Typically in computing, data is entered through various forms (input) into a computer, the data is often manipulated, and then information is presented to a human (output). Typical output devices: Monitors* Pixels: Images are created with dots of lights called picture elements, or pixels. More pixels = higher resolution. Resolution is the maximum number of pixels the monitor can display * Basic VGA is a pixel grid 640 X 480 * Super VGA is 1,024 X 768 * A video card, (also referred to as a graphics accelerator card, display adapter, graphics card, and numerous other terms), is an item of personal computerhardware whose function is to generate and output images to a display. Printers * Laser - laser beams bond toner to paper * Ink jet - fine stream of ink * Dot Matrix - pins & ribbon What else can you think of?

4. Storage Storage, or mass storage refers to various techniques and devices for storing large amounts of data. The earliest storage devices were punched paper cards, which were used as early as 1804 to control silk-weaving looms. Modern mass storage devices include all types of disk drives and tape drives. Mass storage is distinct from memory, which refers to temporary storage areas within the computer. Unlike RAM memory, mass storage devices retain data even when the computer is turned off. The smallest unit of storage is a file that contains such data as a resume, letter, budget, images or any one of the thousands of items that you may have saved for future reference. Additionally, files can be executable program files, or system files reserved for the operating system. Mass storage is measured in kilobytes (1,024 bytes), megabytes (1,024 kilobytes), gigabytes (1,024 megabytes) and terabytes (1,024 gigabytes). Examples of some mass storage devices * Disk storage - hundreds of thousands of cycles latency, but very large ** Floppy Disks: Relatively slow and have a small capacity, but they are portable, inexpensive, and universal ** Hard disks : Very fast and with more capacity than floppy disks, but also more expensive. Some hard disk systems are portable (removable cartridges), but most are not. * Tertiary storage - ** Optical storage: Unlike floppy and hard disks, which use electromagnetism to encode data, optical disk systems use a laser to read and write data. Optical disks have very large storage capacity, but they are not as fast as hard disks. Examples: CD, CD-R, CD-RW, DVD or DVD-R ** Tapes: Relatively inexpensive and can have very large storage capacities, but they do not permit random access of data. * Flash Memory - faster than disk storage, with up to 4GB or more of data, transferring (usually) over universal serial bus (USB) POONAM VALERA GUJRAT JAMNAGAR p_aum_k@yahoo.co.in