PERKEMBANGAN DAN KLASIFIKASI KOMPUTER Era sebelum th.1940 Ribuan tahun lalu(sebelum masehi) di cina ditemukan abacus/sempoa 1617, john napier menciptakan metode logaritma yang dinamakan napier s bones. Alat ini dapat dipakai untuk melakukan operasi penambahan, pengurangan, perkalian, pembagian, yang sebelumnya secara sederhana oleh Abdullah Muhammad ibn musa al khwarizmi. Al khwarizmi seorang ahli matematika dari Uzbekistan yang hidup di masa tahun 770-840 masehi, telah menemukan konsep algoritzm. Pada tahun 1642 blaise pascal menciptakan mesin hitung mekanik yang pertama yang diberi nama pascaline. Tahun 1822 charles babbage yang digelar bapak computer telah merancang apa yang dinamakan difference engine. Yang selanjutnya dikembangkan menjadi analytical engine pada tahun 1833 oleh george scheutz pada tahun 1855 dan pada tahun 1889, digunakan sebagai mesin kilang analitik semua computer pada saat menggunakan model mesin seperti yang dirancang oleh babbage yang terdiri atas input, memori, pemrosesan dan output. Pada tahun 1854, ahli matemtika dari inggris, george boole telah mencipta satu bidang algebra. Pada tahun 1937 howard aiken memperkenalkan mesin yang dibuat dari komponen-komponen mekanik dan elektronik yang dinamai MARK 1. mesin ini biasa menyelesaikan masalah fungsi trigonometri dan dasar perhitungan matematika. Setelah itu baru mulai tahun 1940 muncul teknologi baru computer dengan perangkat elektronik digital.
Era setelah th.1940 1. Generasi pertama(1940-1959) ENIAC (electronic numerical intergrator and calculator) merupakan generasi pertama computer digital elektronik yang digunakan untuk kebutuhan umum. Dibuat pada tahun 1943 oleh Dr.John W. Mauchly dan John Presper Eckert di moore school of electrical engineering (University of Pennsylvania) dan baru selesai pada tahun 1946. ENIAC berukuran sangat besar, untuk penempatannya, membutuhkan ruang 500 m2. ENIAC menggunakan 18.000 tabung hampa udara, 75.000 resistor. Ketika dioperasikan, ENIAC membutuhkan daya listrik sebesar 140 kilowatt dengan berat lebih dari 30 ton, dan menempati ruang sekitar 167 m2. Mesin Van Neuman, dikembangkan tahun 1945 oleh seorang ahli matematika yaitu john von neuman yang juga merupakan konsultan proyek ENIAC. Dia memberikan gagasan sebagai stored-program concept, yaitu sebuah konsep untuk mempermudah proses program agar dapat dipresentasikan dalam bentuk yang cocok untuk penyimpanan didalam memori untuk semua data. Gagasan juga dibuat hampir pada
waktu yang bersamaan oleh Turing. Selanjutnya Von Neuman mempublikasikan dengan nama baru yaitu EDVAC (electronic discrete variable computer). Dengan mesin tersebut disebut sebagai generasi pertama computer eletronik terprogram modern yang disediakan secara komersial dengan nama EDVAC, EDSAC (electronic delay storage automatic calculator) dan UNIVAC 1 dan 2 (universal automatic computer) yang dikembangkan oleh Eckert dan Mauchly. Untuk pertama kalinya computer tersebut menggunakan RAM (random access memory) untuk menyimpan bagianbagian dari dan data yang diperlukan secara cepat. Dengan konsep itulah John Van Neuman dijuluki sebagai bapak computer modern pertama di dunia, yang konsepnya masih digunakan sampai sekarang. Von Neuman juga merupakan orang yang pertama mencetus istilah game theory yang kemudian berkembang menjadi ilmu tersendiri. Game theory bermanfaat untuk mensimulasikan game, seperti catur, bridge, dan sejenisnya. Dia juga bermanfaat untuk mensimulasikan perang ( penting di dunia pertahanan). 2. Komputer generasi kedua (1959-1964) Computer generasi kedua ditandai dengan ciri-ciri sebagai berikut: Menggunakan teknologi sirkuit berupa transistor dan dioda untuk menggantikan tabung vacuum. Sudah menggunakan operasi bahasa pemrograman tingkat tinggi seperti FORTLAN dan COBOL. Kapasitas memori utama dikembangkan dari magnetic core storage. Menggunakan simpanan luar berupa magnetic tape dan magnetic disj. Kemampuan melakukan pemrosesan real-time dan real-sharing. Ukuran fisiknya sudah lebih kecil dibandingkan computer genersi pertama. Proses operasi sudah lebih cepat, yaitu bisa dapat melakukan jutaan operasi per detik. Kebutuhan akan daya listrik lebih kecil. Orientasinya program tidak lagi tertuju pada aplikasi bisnis, tapi juga sudah ke aplikasi teknik. Pada pertengahan tahun 1950 UNIVAC mengalami kemajuan dalam beberapa aspek pemrograman tingkat lanjut, sehingga merupakan computer general propose (tujuan umum) pertama yang didesain untuk menggunakan pita magnetic sebagai media input dan output-nya. Hal ini ynag dianggap sebagai tahun kelahiran industri computer yang didominasi perusahaan IBM dan Spery. Dan computer UNIVAC pertama kali digunakan untuk keperluan kalkulasi sensus di AS tahun 1951, dan dioperasikan sampai 1963. Selain itu IBM memproduksi IBM 605 dan IBM 701 pada tahun 1953 yang berorientasi pada aplikasi bisnis dan merupakan computer paling popular sampai tahun 1959. IBM 705 dikeluarkan untuk menggantikan
IBM 701 yang kemudian memantapkan IBM dalam induetri pengilahan data. Dibandingkan dengan tabung, teknologi transistor jauh lebih efisien sebagai switch dan dapat diperkecil ke skala mikroskopik. Era ini juga menandakan permulaaan munculnya minicomputer yaitu DEC PDP-8 dibuat pada tahun 1964 untuk keperluan pengolahan data komersial. Jenis-jenis computer lain yang muncul pada generasi ini adalah UNIVAC III, UNIVAC SS80, SS90 dan 1107, Burroughs 200 (pabrik pembuatnya Burroughs), IBM 7070, 7080, 1400, dan 1600 (pabrik pembuatnya international business machine) Honeywell 400 dan 800 (pabrik pembuatnya honey well), CDC 1604 dan 160A (pabrik pembuatnya control data corporation), serta GE 635, 645 dan 200 (pabrik pembuatnya general electric). 3. Komputer generasi ke tiga (1964-1970) Cirri-ciri computer generasi ketiga adalah: Menggunakan IC, maka kinerja computer menjadi lebih cepat dan tepat. Kecepatannya hamper 10.000 kali lebih cepat dari computer generasi pertama. Peningkatan dari sisi software. Kapasitas memori lebih besar, dan dapat menyimpan ratusan ribu karakter (sebelumnya hanya puluhan ribu). Menggunakan media penyimpanan luar disk magnetic(external disk) yang sifatnya pengaksesan data secara acak (random access) dengan kapasitas besar (jutaan karakter). Penggunaan listrik yang lebih hemat. Kemampuan untuk melakukan multiprocessing dan multitasking. Telah menggunakan terminal visual display dan dapat mengeluarkan suara. Harga yang semakin murah. Kemampuan melakukan komunikasi dengan computer lain. Mulai generasi ke tiga inilah teknologi IC menjadi ciri utama karena mulai digunakan pada sebuah perangkat computer hingga generasi sekarang. Komponen IC berbentuk hybrid atau solid (SLT) dan monolithic (MST). MST adalah elemen transistor, dioda, dan resistor diletakkan bersama dalam suatu chip. MST lebih kecil tapi mempunyai kemampuan lebih besar dibandingkan SLT. 4. Komputer generasi ke empat (1970-1980-an) Ciri-cirinya: Merupakn kelanjutan dari generasi ke tiga. Bedanya bahwa IC pada generasi ke empat lebih kompleks dan terintegrasi. Sejak tahun 1970 ada dua perkembangan yang dianggap sebagai computer generasi ke empat. Pertama, penggunaan LSI (large scale integration) yang disebut juga dengan nama bipolar large scale integration. LSI merupakan pemadatan beribu-ribu IC yang dijadikan satu dalam sebuah keeping IC yang disebut
chip. Istilah chip digunakan untuk menunjukkan suatu lempengan perdegi empat yang memuat rangkaiaan terpadu IC. LSI kemudian dikembangkan menjadi VLSI (very large scale integration) yang dapat menampung puluhan ribu hingga ratusan ribu IC. Selanjutnya dikembangkannya computer mikro yang menggunakan microprocessor dan semiconductor yang berbentuk chip untuk memori computer internak sementara generasi sebelumnya menggunakan magnetic core storage. Perusahaan intel pada tahun 1971 memperkenalkan mikro computer 4 bit yang menggunakan chip prosesor dengan nama 4004 yang berisi 230 transistor dan berjalan pada 108 KHz dan dapat mengeksekusi 60.000 operasi perdetik. Dilanjutkan pada tahun 1972 intel memperkenalkan mikrokomputer 8008 yang memproses 8 bit informasi pada satu waktu. Selanjutnya mikroprosesor 8080 dibuat pada tahun 1974, dan merupakan prosesor untuk tujuan umum pertama. Sebelumnya adalah prosesor 4004 dan 8008 dirancang untuk kebutuhan aplikasi tertentu. Prosesor 8080 kemampuannya lebih cepat dan memiliki sel instruksi yang lebih kaya, dan memiliki kemampuan pengalamatan yang lebih besar. Pada generasi ke empat ini tampilan monitor masih satu warna (green color).
5. Komputer generasi ke lima (1980-an - ?) Cirri-cirinya: Mulai diproduksi PC missal tahun 1980 oleh IBM, yang terkenal dengan IBM-PC, yang selanjutnya dikuasai intel untuk hardwarenya dan Microsoft untuk softwarenya. Prosesor yang digunakan adalah 8088/8086 yang menjadi standar computer saat itu, yang menggunakan basis dengan proses 16 bit per satu waktu. Telah dilakukan pengembangan dengan apa yang dinamakan josephson junction, teknologi yang akan menggantikan chip yang mempunyai kemampuan pemrosesan trilyunan operasi per detik. (sementara teknologi chip hanya mampu memproses milyaran operasi per detik). Computer mampu menterjemahkan bahasa manusia, manusia dapat langsung bercakap-cakap dengan computer serta penghematan energi computer. Sifat luar biasa ini disebut sebagai artificial intelegence . Berbasis GUI (graphic user interface), multimedia, multikomunikasi.
COMPUTER NETWORKING Computer networking is a linking of the network devices and computers with each other to provide the data communications and sharing the network resources such as printer, scanner, modem, CD/DVD and internet access. A computer network can be interconnected with the UTP/STP cables, coaxial cables, fiber optics and wirelessly through the radio waves. Today, no business can work effectively without the data communications within the organization. A network can be designed by different layouts known as topologies. The common topologies include star, hub, mesh, hybrid and ring. Star topology is the most common topology in Ethernet based local area network. There are specialized rules and standards and based on these standards, the devices communicate with each other. One of these specialized standards and agree up ways is known as protocols. TCP/IP is the protocol suite that contains the multiple communication protocols such as TCP, IP, SMTP, FTP, DHCP, LDAP, PPP, Telnet and many others. TCP/IP works together and it is the most common communication protocol for the LAN, WAN and internet. The communications on the internet is based on the IP addresses, which is a part of the TCP/IP stack. No computer on the internet or in the LAN/MAN/WAN can communicate without a unique IP address. Networking and data communications provides the flexibility, easy of work and communications with each other and today every kind of business in the world, which involves more than one computer, require a computer network. A network can be setup by using the following things. Computer with Windows/Linux operating system installed. Every computer requires a unique LAN card, which should be properly installed and configured. Ethernet cable with the RJ-45 connectors at both ends. A Router/Switch or hub. The other devices are bridges, transceivers, terminal servers and gateways and they can be setup according to your requirements. There are three main types of the computer network i.e. LAN, MAN, WAN, CAN, GAN and PAN and each network either be a peer to peer or client server network. In a client/server network model, a centralized domain controller is used to control all the computer network. It provides the services to the clients like logon authentication, printer access, scanner access, centralized data storage, user management, resources management, DHCP, DNS, FTP and internet access.
To communicate with the other computer, each computer should support the same protocol and the TCP/IP is the most commonly used protocol in a computer network. Internetwork is a type of computer network that connects the two or more different networks. There are three main types of the internetwork i.e. intranet, extranet and internet.
What is RAM? RAM operates much like a human being's short-term memory. Much like the human brain RAM is able to draw upon the computer's long term memory for information. This is often necessary when short term memory becomes full. Most computers come equipped with at least 256 million RAM bytes plus the hard disk which has the capability of holding 40 billion bytes. Anyone who works as their own tech geek on their computer system may be highly concerned about what is ram? It is a very important piece of a computer system. It is Random Access Memory which is the location where the application programs, the operating system, and data presently in use are stored. This way the computer's processor has the ability to reach them momentarily when needed. RAM is head and shoulders above the other various types of storage inside a computer system. It's even faster than floppy disk, hard disk, or CD-ROM. The information stored in RAM is only accessible for the length of time that a computer is begin run. Information previously stored in RAM disappears when a computer is shut down. When the computer is turned back on, information from hard disk is retrieved to bring RAM back to the forefront again. RAM is much like main memory that is accessible by programs.
How Does it Work? RAM operates much like a human being's short-term memory. Much like the human brain RAM is able to draw upon the computer's long term memory for information. This is often necessary when short term memory becomes full. Most computers come equipped with at least 256 million RAM bytes plus the hard disk which has the capability of holding 40 billion bytes. Data is placed on a magnetized area that resembles a record. Computer printers also hold bytes of RAM as well. Each byte of RAM has the ability to be ascertained separately without the other bytes being accessed.
Types of RAM RAM comes in dual forms. DRAM which is Dynamic Random Access Memory and SRAM which is Static Random Access Memory. DRAM is the most typical of the two types. DRAM requires refreshing at a rate reaching in the thousands each second. DRAM's times for accessing information are 60 nanoseconds. SRAM is more costly, but
does operate at a much quicker pace than DRAM. The interlocking of a capacitor and a transistor produces a memory cell. This is one bit of data. Also, SRAM allows access at times as quick as 10 nanoseconds.
What is a VLAN? A Virtual Local Area Network (VLAN) is a group of hosts that feature a like set of requirements and can communicate as though they were all connected via the same wires. A Virtual Local Area Network (VLAN) is a group of hosts that feature a like set of requirements and can communicate as though they were all connected via the same wires. However, unlike a traditional LAN, a VLAN is not necessarily all in the same place, and the hosts involved in the network can be located practically anywhere. All VLANs have the exact same attributes as a traditional physical local area network, though they can be configured via software instead of having to actually relocate the hosts. Many VLANs are designed as replacements to the services that are traditionally provided by routers on physical LANs. VLANs are able to tackle issues like network management, security, and scalability with ease. VLANs are known as Layer 2, or Data Link layer, constructs which transfer data between network nodes. Because they are Layer 2 constructs, they can interface with Layer 3 IP subnets with a one to one relationship.
How are VLANs designed? The IEEE assigned IEEE 802.1Q as the protocol by which to configure virtual LANs. IEEE 802.1Q provides for a header with a 2-byte protocol identifier and another 2-byte tag control information. These are known as TPID and TCI, respectively. The TPID is fixed at 0x8100 while the TCI contains information pertaining to the user priority, canonical format indicator, and VLAN identifier.
What are the two types of VLAN memberships? VLAN membership can be assigned in one of two ways. Static or Dynamic. A Static VLAN is also known as a port based VLAN. These types of VLANs are created by assigning specific ports to a VLAN. As new devices enter into the VLAN network, the device assumes a specific port. If end users change ports but require access to the same VLAN, network administrators are required to assign new port to VLAN assignments for the new port.
A Dynamic VLAN is designed to be easily configured using software. The most common software for designing dynamic VLANs is CiscoWorks, a program developed by Cisco. A VLAN Management Policy Server (VMPS) must be set up first for a dynamic VLAN. This server will allow the VLAN to automatically switch ports whenever new devices connect to the VLAN. It uses information such as the device s ports, unique usernames, and MAC addresses to determine whether or not to change ports to fit the needs of the incoming device
How to Use Windows ScanDisk? If you ever need to test the function of your hard drive, then you should learn how to use this great free disk-checking program included with your Windows system... I love ScanDisk. Honestly, I do. As a computer support specialist with over 18+ years of experience, I often had to use this great little utility. It's fairly powerful, works on all versions of Windows and best of all is free since it comes bundled inside Windows.
So what is it? ScanDisk is disk-checking and diagnostic tool that you can use to test your hard drive. It can also be used repair problems on magnetic media; hard disk and floppy disks.
Why use ScanDisk? It's a very easy to use program and even the most non-technical person can learn how to use it. It can quickly fix most common disk errors. And I did mention it's installed as a part of Windows so it is always available. If you can boot into Windows, then you can use the program. How to use it in Windows 98/98SE/Me: 1) Close all programs. 2) Click on the "Start" button. 3) Go to "Programs" 4) Scroll to "Accessories" 5) Click on "System Tools" 6) Select "ScanDisk" 7) Now locate and select the drive you want to check (C:\). 8) Check the "Standard" radio button.
9) Check the "Automatically Fix Errors" 10) Click "OK" to run. How to use it in Windows 2000/XP/Vista 1) Close all programs before you begin. 2) Click on the "Start" button then "My Computer". 3) Right click on drive you wish to scan and then click on "Properties". 4) Now you click on the "Tools" tab at top of pop-up window. 5) Click on "Check Now" in the "Error Checking" section. 6) Check the "Automatically Fix Errors" 7) Click "OK" to run. Testing Options in Windows 98/98SE/Me: Standard: This option basically only checks files and folders for Windows system errors. This is good for routine maintenance checks. Thorough: This option is not used often due to time constraints. Don't check "Thorough" unless you can let the machine run uninterrupted for several hours (2+ on larger drives) or overnight. I'm not kidding. Thorough is used for when you are having severe hard drive issues only. When you have to check your drive for possible physical damage, check "Thorough" and then select, click "System and Data Areas" Testing Options in Windows 2000/XP/Vista: The "Standard" function in the older version is now the default. Just with click "Automatically Fix Errors" To use a thorough scan to check for both system and physical errors, you should also check "Scan For and Attempt Recovery of Bad Sectors." To run scandisk in Windows 2000/XP/Vista you have to have programs closed down, or you will keep getting a error message, "Disk check could not be performed because exclusive access to the drive..." If this keeps happening then if possible restart your computer and press "F8" after PC the logo but before Windows starts. This will let you into Windows "Safe Mode". You can run ScanDisk now but be warned it will take twice as long but will give you the same results. ScanDisk Test Results:
After processing you should get a pop-up window with the results of your test. The important to look for is "Bytes in bad sectors". This shows the number of bytes that have been marked bad or basically unusable for storage. It's normal to have a small number of bytes in bad sectors (less than 100,000). But more than this or an increased number over time is sign for keeping your file backups up to date and saving for that bigger, better hard drive.
The Adware Threat Adware can be basically defined as software that tracks your activities on the Internet so that it can trigger off pop-up ads and other marketing-related actions. The Internet has many free adware removal tools, which can help you run a scan to remove adware. When your computer slows down and behaves strangely, chances are you have adware installed. You didn't ask for it, but neither did you ask for new toolbars, websites you don't recognize, continuous popups! Read on to know just how annoying and dangerous adware can be. Adware doesn't let your computer respond quickly to your commands. When you click to go to a website, it takes you elsewhere and you wonder why. Adware presents you with toolbars you never asked for and keeps adding strange new websites to your favorite folder so that it looks like you gave it permission to be there. Here's the worst part - it steals your personal information, spies on you and sells this information to advertisers who can then irritate you with a flood of advertisements that they think you are interested in.
Nobody Is Spared From Adware Practically every computer that connects to the Internet has loads of spyware and adware getting into it, collecting confidential information from the user. This can be in the form of information about browsing habits, or more serious threats like spying on your credit card number, and other personally identifiable information so that it can misuse it and put you in danger. Adware can be basically defined as software that tracks your activities on the Internet so that it can trigger off pop-up ads and other marketing-related actions. It installs components in your system without your being aware of it so that it can collect personal data like surfing habits and other demographics. Saying no when adware asks you has nothing to do with what it does. It just goes right ahead and installs itself in your system.
In recent times, adware and spyware have been evolving so fast that it is more than adware removal tool manufacturers can do to keep up with them. Adware poses a major security risk to any computer and every user must make it a point to ensure that he or she runs a scan to clear their systems from adware and spyware. The Internet has many free adware removal tools, which can help you do this. But you've got to be cautious in selecting a reliable vendor. There's every chance that a vendor who promises to remove all the adware from your computer will do just the opposite - that is, install more spyware and adware. Reliable adware removal tools can protect you against unwanted intruders like adware in your system. Look around and compare the features of various paid adware removal tools available. While some free adware removal software will only scan your computer and present you with the results, they won't actually clean it from your computer until you buy it. Beware of this ruse.
