T.ringkasan alpro 3

COMPUTER AND PROGRAMMING


In everyday life we ​​often use the computer as to create a table for a presentation or make his progspecially for high school informatics.
The first computer was built around 1930 by Dr. John Atanasoff. and Clifford Berry at Iowa State University. Atanasoff computer designed to assist graduate students in nuclear physics with their mathematical calculations. The first large-scale, general-purpose electronic digital computer, called ENIAC, completed in 1946 at the University of Pennsylvania with funding from the U.S. Army. It weighs 30 tons and takes up space 30-by-50-foot, ENIAC used to compute ballistics tables, predict the weather, and make atomic energy calculation.
But with advances in technology it is now peasat computer using the name of its processors. And now with less money over $ 1000 will get the computer.The elements of the existing computer hardware and software 2. Hardware is hardware like monitor, cpu, keyboard, mouse and others. And the software is an example of software applications that run progaram or computer.
Computer Hardware
Although very expensive haraga computer but still same.Such kompenen computer hard disk, fd, dvd, cpu, processor, memory, keyboard and others much more.
 Memory is a very important kompenen on the computer because the memory can store any data or software. And the computer knows only the language support machines are 0 and 1.
  the contents of the memory cell is the number 3? 26 and the contents of the memory cell 4 is the letter H. Although not shown in Fig. 1.4, memory cells can also contain program instructions.


Byte and Bits A memory cell is actually a grouping of smaller units called bytes. Byte is the amount of storage required to store one character, like the letter H in Figure 4 memory cells. 1.4. The number of bytes of memory cell can contain varies from computer to computer. A byte consists of units smaller storage called bits (Figure 1.5). Bit long, derived from the words b inary dig it, is the smallest element of a computer can handle.

 shows some of the secondary storage device and the most common storage media. Most personal computers use two types of hard disk as a secondary drive them hard-storage devices and optical drives. Hard disks are attached to the disk drive and coated with magnetic material. Every bit of data is on the disk magnet, and place arranged in concentric circles called tracks.
It was a hard disk on a personal computer usually hold a few hundred gigabytes (GB) of data, but the hard drive that stores data for the entire network can provide sebagaisebanyak several terabytes (TB) of storage (see Table 1.1).
One CD can hold 680 MB of data. A DVD uses a small hole packed in a tight spiral, allowing storage of 4.7 GB of data on a single layer. Some four-layer DVD can store data-two on each side for a total capacity of 17 GB, enough storage for nine hours of studio-quality video and multi-channel audio.
Flash drive as illustrated in Fig. 1.6 flash memory packaged in a small plastic case about three inches long that can be connected to one of the computers USB (Universal Serial Bus) port. Unlike hard drives and optical drives have to spin the disk up for access to data, flash drives have no moving parts and all data transfer is the only electronic signals. Typical USB flash drive to save 1 to several GB of data, but the 64-GB drives are also available.
 Central Processing Unit
The central processing unit (CPU) has two roles: coordinating all computer arithmetic and logical operations and data. CPU following the instructions contained in a computer program to determine the operation to be done and in what order. It then sends a signal to coordinate control other computer components. For example, if the instruction requires scanning the data item, the CPU will send control signals required for input devices.

We have experienced an explosion in access to information around the world is largely due to the fact that computers are now linked together in a network so that they can communicate with each other. Usually using lan, modem and others.
 In a local area network (LAN), computers, and other devices in a building connected to the wired or wireless network, which enables them to share information and resources such as printers, scanners, and a secondary storage device . A computer that controls access to the secondary storage devices such as hard disk called the file server. Local area network can be connected to other LANs that use the same technology as the telephone network.
WAN is the Internet, a network of universities, corporations, government, and publicaccess network. Internet is a descendant of the computer network ARPAnet project designed by the 1969 U.S. Department of Defense. The purpose of the project is to create a computer network that can continue to operate even if partially destroyed. The most widely used aspect of the Internet is the World Wide Web (WWW), the universe of Internet accessible resources are navigable through the use of a graphical user interface (GUI).
 In this case, the prompt is mycomputer: ~> (In this figure and in all subsequent figures show aired the program, the input typed by the user is displayed in color to distinguish it from the computer-generated text.)
Figure 1.10 shows the window that appears on the Microsoft Windows 7 when you left-click on the Start icon and then left click on Computer. You can see the directory of your hard drive (C :), the backup drive (F :), optical drive (D :), or flash drive (E :) by double-clicking the appropriate icon.
  Let's use the situation described in Fig. 1:12-executes the program stored in the memory of water bills-as an example. The first step of the program into memory scan data that describes the amount of water used. In step 2, the program manipulates the data and stores the results of the calculations in the memory. In the final step, the calculation is shown as the water bill.
Software Development Methods
Programming is a problem-solving activity. If you are a good problem solver, you have the potential to become a good programmer.
Software Development Methods
1. Determine the requirements of the problem.
2. Analyze the problem.
3. Design algorithms to solve the problem.
4. Implementing algorithms.
5. Test and verify the program is completed.
6. Maintain and update the program.

 PROBLEM
Determining the requirements problem forces you to declare the problem clearly danjelas and to get a clear understanding of what is required for you is to eliminate solusinya.Tujuan important aspects and zero in on the root of the problem.
ANALYSIS
Analyzing the problem involves identifying the problem (a) input, ie, the data you have to work with, (b) output, which is the desired result, and (c) any additional requirements or constraints on the solution. At this stage, you must also specify the required format in which the results should be displayed (eg, as a table with a specific column headings) and develop a list of variables and their relationship problems. This relationship can be expressed as a formula.
DESIGN
Designing algorithms for solving the problem requires you to develop a list of steps is called an algorithm to solve the problem and then verify that the algorithm solves the problem as intended. Writing algorithms is often the most difficult part of the problem-solving process.