The leaders of the computer

1822
Charles Babbage propose an idea about the tools that can help men perform in a complex calculation. The engine is not finished at this time made in the London Museum of Science.

1937
Dr. John V Atanasoff and Clifford Berry designed the first electronic digital computer. With the ABC (Atanasoff-Berry Computer). ABC can only calculate and add less.

1943
During World War 2, a British scientist named Alan Turing electronic computer designed specifically for the UK army. Code used to penetrate German defense.

1944
Howard Hathaway Aiken (american) make Mark I. A first digital calculating machine that is made. Has a 7.45 feet wide x 50 feet, with a weight of 35 tons. Mark I can be used to calculate the probability.

1945
Dr. John von Neumann concept of write data storage. When the idea was still in form.

1946
Dr. John W. Mauchly and J. Presper Eckert, jr. complete large-scale computer first, given name of ENIAC (Electronic Numerical Integrator And Computer). The world knows these two men as the inventors computer.
ENIAC weight 30 tons, consisting of 18,000 light tube (transistor size), has a 30 foot wide x 50 feet, use of 160,000 watts. The first time the computer is switched on, the entire electricity network in the Philadelphia sudden death.
ENIAC could calculate not only to less time for, but can also be programmed to perform a simple process. Compared to the Mark I can only calculate, can be seen that the ENIAC was the first computer in the world.

1947
Found by the first transistor William Shockley, John Bardeen and Walter Brattain. Since the transistor is found, the size of the computer off ..

From reading above, the inventors note that the computer (not a calculator) is a PhD. John W. Mauchly and J. Presper Eckert, jr ..
Source:
Book Discovering Computers: Concept for a Digital World 2003; Garry B. Shelly, Thomas J. Cashman, Misty E. Vermaat.

This book is the Scripture is the Hardware Computers. And a chance to learn H / W.. If you want to know more, please buy it.

Division of IP Address Class

Division of IP Address Class

Number of IP address that is theoretically available 255x255x255x255 around 4 billion or more that must be distributed to all internet users throughout the world. The division of classes is intended to facilitate the allocation of IP Address, better for the host / network or for certain specific purposes.

IP Address can be separated into 2 parts, namely the network (net ID) and the host (host ID). Net ID to participate in the identification of a network from another network, while the host ID identifies a role for the host in a network. So, all hosts are connected in the same network have the same net ID. Some of the bit-bit from the beginning of the IP Address is the network bit / network number, while the rest is for the host. Dividing line between the network and the host is not fixed, depending on the class network. IP address is divided into five classes, namely class A, class B, class C, class D and class E.

Differences in each class is on the size and amount. For example IP class A network used by a few but the number of hosts that can ditampung by each network is very large. Class D and E is not used in general, the class D is used for network multicast, and class E for experimental keprluan. Internet Protocol software determines the type of division of this class with a few test bits of the first IP Address.

The first bit IP address class A is 0, with the long 8-bit net ID and host ID length of 24 bits. Be the first byte IP address class A has a range from 0-127. So there is in the 127 class A network with each network can accommodate about 16 million hosts (255x255x255). IP address assigned to the class A network with the number of hosts that are very large.
IP address class A
Two-bit IP address class B is always set to 10 so that the first byte is always worth between 128-191. Network ID is 16 bit and 16 bit host ID and the rest is so that if the computer has IP address 167.205.26.161, the network ID = 167205 and host ID = 26161. On. IP address class B has a range of IP from 191.155.xxx.xxx to 128.0.xxx.xxx, ie, the network was 65,255 with the number of hosts in each network host 255 x 255, or approximately 65 thousand hosts.


IP address class B
Class C IP address is used to initially small-sized networks such as LAN. Bit the first three class C IP address is always set to 111. Network ID consists of 24 bit and 8-bit host ID, so can the rest of about 2 million network with each network has 256 hosts.




Class C IP address
Class C IP address used for multicasting. 4-bit first-class C IP address is always set to 1110 so that the first byte in the range of 224-247, while the next bit-bit is set according to the needs multicast group that uses this IP address. In multicasting is not known term network ID and host ID.
Class E IP address is not for public use. First 4-bit IP address class is set in 1111 so that the first byte in the range of 248-255.
Also known as the additional term Network Prefix, which is used for the IP address that refers to the network prefix is jaringan.Penulisan with a slash "/" followed by numbers that indicate the network prefix length in bits. Eg to appoint a class B network 167.205.xxx.xxx used 167205/16 writing. Figures 16 is a bit long for the network prefix class B.


Configure TCP / IP
Implementation of the TCP / IP protocol on Windows98 includes standard TCP / IP, with kompatible
TCP / IP-based network. Standard protocol TCP / IP, including:
1. Internet Protocol,
2. Transmission Control Protocol (TCP),
3. Internet Control Message Protocol (ICMP),
4. Address Resolusion Protocol (ARP),
5. User Datagram Protocol (UDP).
TCP / IP must be configured before the first order to "communicate" in the network
computer. Each card is a computer network has been installed and requires a subnet IP address
mask. IP address must be unique (different from the other computers), the subnet mask is used to
distinguish the network ID of the host ID.
Provide IP Address
IP address and subnet mask can be provided automatically using Dynamic Host
Configuration Protocol (DHCP) or manually disi.



Procedures are conducted to fill in IP address:
1. Open the Control Panel and double-click the Network icon.
2. In the Configuration tab, click TCP / IP is in the list for network cards that have been
installed.
3. Click Properties.
4. In the IP Address tab, there are 2 options:
* Obtain an IP address automatically
Akan IP address obtained through DHCP facilities. DHCP function to provide IP address
automatically on a computer that uses TCP / IP. DHCP working relationships with
client-server, the DHCP server provides the IP address of a group that can be given
on the DHCP client. In providing this IP address, DHCP IP address only lend
it. So the IP address this ongoing dynamic.
* Specify an IP address
IP address and subnet mask manually filled.
5. Click OK.
6. If necessary re-entry to the dialog box in the TCP / IP Properties, click the Gateway tab,
enter the server address.
7. Click OK.
8. If required to activate the Windows Internet Naming Service (Wins) server, re -
in the dialog box to TCP / IP Properties, click the Wins Configuration tab, and click Enable
Wins Resolution and number of entries the server address.
9. If required to activate the domain name system (DNS), back to the box
dialogue TCP / IP Properties, click the DNS Configuration tab, click Enable DNS, enter the number
the server address.
10. Click OK.

BASIC CONCEPT NETWORK (LAN) Local Area Network

NETWORK computer is a collection of computers, printers and other equipment that is connected in one unit. Information and data moving through the cable-cable or without cable so that the computer network allows users to exchange documents and data, the print on the printer and the same with the hardware / software that is connected in a network.

1) Type of network
In general, a computer network consisting of five types:
a) Local Area Network (LAN), a network of private property in a building or campus-sized to several kilometers. LAN is often used to connect personal computers and workstations in a company office or factory for shared resources (resouce, for example, printers) and exchange information.
b) Metropolitan Area Network (MAN)
Metropolitan Area Network (MAN), basically a wireless version of the larger size and usually use the same technology to the LAN. MAN may include the company's offices are also located close to or a city and can be used for personal (private) or public. MAN is able to support data and voice, can even relate to the cable television network.
c) Wide Area Network (WAN), its scope covers a wide geographical area, often covering a country and even continent. WAN consists of a collection of machines that aim to run the programs (applications) user.
d) Internet
In fact there are many networks in the world, often using the hardware and software that is different. People are often connected to the network hopes to be able to communicate with other people connected to the other network. Desire such as this requires a relationship between a network that is often not compatibel and different. Usually to do this required a machine called a gateway in order to make contact and conduct the necessary translation, both hardware and software. Terinterkoneksi collection of networks that is what is called the Internet.
e) Wireless (Networking without cable), cable network without a solution to komukasi that can not be done with the network cables. For example, people who want to get information or make communication even when the car is above or aircraft, the network is absolutely necessary because without a cable connection cable may not be made in the car or plane. At this time without a network cable is used with a flare using the satellite service and is able to provide access speed faster than the network cables.
2) Network topology
Topology is a way of connecting a computer with other computers so that the network formed. That at this time how many are used Bus, Token-Ring, and Star Network. Each topology has unique characteristics, with its own advantages and kekurangannya.

a) Bus topology
Bus topology is used on a single cable or cable center in which all workstations and servers are linked.


Gambar3. Network topology bus

Benefits
Save the cable
Cable layout simple
Development of the network or adding new workstation can be done easily without disrupting other workstation
Losses
Fault detection and isolation is very small
Density of the traffic on main routes
Weakness of this topology is when there is interference in the center of the cable along the entire network to crash akan
Repeater is required for long-distance

b) Token Ring topology
In the Ring topology all workstations and servers linked to form a pattern so that the circle or ring. Each workstation or server will receive and pass information from one computer to another, if the addresses are the appropriate information is received and when the information will not be missed.



Figure 4. Topology network Token-Ring

Weakness of this topology is each node in the network will always be involved to manage the information missed in the network, so that when there is interference of a node in the entire network will be disrupted.
Ring topology is the benefits of a collision or no collision of data such as the Bus topology, because only one node can transmit data at a time.

c) Star topology
In the Star topology, each workstation is connected directly to a server or hub. The advantages of this topology type Star is that with the cable for each workstation to the server, or the wide bandwidth communication channels in the cable so that the width of the akan akan improve network performance overall. And also when there is a disruption in the cable path interference will only occur in the communication between the workstation with the server, the network as a whole does not experience interference. Weakness of the Star topology is the cable that needs greater than the other topology.

Figure 5. Star Network topology

Benefits
Most flexible
Installation / changes to the station is very easy and does not disrupt the network
Centralized control
Ease of detection and fault isolation / damage management network
Losses
Spendthrift cable
Need special handling
Control center (HUB) be a critical element
4) Type Network
Network type closely related to the network operating system. There are two type network, the client-server type network and peer to peer.

a) Client-Server Network
Servers are computers that provide facilities for the other computers in the network and client-computer is the computer that receives or uses facilities provided by the server. Server in the network client-server type is called the Dedicated Server as pure as the server that provides the facility to the server and the workstation can not act as a workstation.
Excellence
More high-speed access for the provision of facilities and network management is done exclusively by a single computer (server) that is not burdened with other tasks, such as a workstation.
System administration and network security is better, because there is a duty as a computer network administrator, who manages the system administration and network security.
Data backup system is better, because in the network client-server backup is done centrally on the server, which will membackup all the data used in the network.
Weakness
Operational costs are relatively more expensive.
Required the existence of a special computer for more berkemampuan assigned as the server.
Of the network depends on the server. When the server to crash the entire network will be disrupted.
b) Peer To Peer Network
When the review of the role of the two types of server network, the network server in the peer to peer type termed non-dedicated server, because the server does not act as a server at once pure but can act as a workstation.
Excellence
Between computers in a network can share each other that it has facilities such as: hard, drive, fax / modem, printer.
Operational costs are relatively cheap compared with the type of client-server network, one of them because they do not require any server that has a special ability to organize and provide facilities network.
Work of the network does not depend on a single server. So when one of the computer / peer dead or damaged, the network as a whole will not experience interference.
Weakness
Troubleshooting a network is relatively more difficult, because in the network peer to peer type of each computer will be able to engage in communication that exists. In client-server network, the communication between the server with the workstation.
Lower performance compared with client-server network, because every computer / peer must manage in addition to the facility network must also manage the job or the application itself.
Network security system is determined by each user to manage the security of each facility owned.
Because the network data in each computer in the network, the backups should be done by each machine.

5) Network Protocol
To carry out various communications vendor computer needed a basic rule that the standard and approved by various parties. As well as two different nations, the need to communicate with translators / interpreters, or a language that is understood both sides.
In the world of computer and telecommunications interpreter with the identical protocol. For that the world body that handled the standardization of ISO (International Standardization Organization) standard to make the rules known by the name of OSI reference model (Open Systems interconnection). Thus, all vendors are expected to telecommunication device model must be guided by this reference in developing protocolnya.
OSI reference model consists of 7 layers, from physical layer up to the application. Reference model is not only useful for LAN products, but in building the Internet even though the network is required. Relationships between the OSI reference model with the Internet protocol can be seen in table 1 below:
Table 1. Relationships between the OSI model with the Internet protocol
OSI Model
TCP / IP
Protocol TCP / IP
No
Layer

Protocol Name
Usefulness
7
Applications
Applications
DHCP (Dynamic Host Configuration Protocol)
Distribution protocol for IP on the network with a limited number of IP



DNS (Domain Name Server)
Data base machine and the domain name IP number



FTP (File Transfer Protocol)
Protocol for file transfer



HTTP (Hyper Text Transfer Protocol)
Protocol to transfer HTML files and Web



MIME (Multipurpose Internet Mail Extention)
Protocol to send a binary file in text form



NNTP (Network News Transfer Protocol)
Protocol to receive and send newsgroups



POP (Post Office Protocol)
Protocol to retrieve mail from the server



SMB (Server Message Block)
Protocol to transfer various file server DOS and Windows
6
Presentations

SMTP (Simple Mail Transfer Protocol)
Protocol for the exchange of mail



SNMP (Simple Network Management Protocol)
Protocol for network menejemen



Telnet
Protocol for remote access from



TFTP (Trivial FTP)
Protocol for file transfer
5
Sessi

NetBIOS (Network Basic Input Output System)
BIOS standard network



RPC (Remote Procedure Call)
Remote procedure calling



Socket
Input Output for the network type of BSD-UNIX
4
Transport
Transport
TCP (Transmission Control Protocol)
Exchange of data-oriented protocol (connection oriented)



UDP (User Datagram Protocol)
Data exchange protocol, non-oriented (connectionless)
3
Network
Internet
IP (Internet Protocol)
Routing protocol to set



RIP (Routing Information Protocol)
Routing protocol to select



ARP (Address Resolution Protocol)
Protocol to get hardware information from the IP number



RARP (Reverse ARP)
Protocol to obtain information from the hardware IP number


(Continued Table 1)
2
Data link LLC
Network interface
PPP (Point to Point Protocol)
Protocol for point to point

Data Link
MAC

Slip (Serial Line Internet Protocol)
Protocol by using the serial connection
1
Physical

Ethernet, FDDI, ISDN, ATM


Standards to network problems not only done by the ISO, but also held by other world bodies such as ITU (International Telecommunication Union), ANSI (American National Standard Institute), NCITS (National Committee for Information Technology Standardization), even by the professional associations IEEE (Institute of Electrical and Electronics Engineers) and the ATM-Forum in the United States. In practice even vendor-vendor LAN products that have generated the IEEE standard.

6) IP Address
IP address is the address given on the network equipment and computer network that uses TCP / IP. IP address consists of 32 bit binary number that can be written as four decimal digit groups separated
by a period such as 193.160.5.1.

Table 2. Example of IP Address
Network ID
Host ID
193
160
5
1

IP address consists of two parts, namely the network ID and host ID, which determine the network ID address of the computer network, while the host ID determines the host address (computer, router, switch). Therefore IP address to give complete address along with a host network address where the host is located.

Class-class IP Address
For ease of use, depending on the needs of the user, IP address is divided into three classes as shown in the table below

Table 3. The division of class IP Address

Class
Network ID
Host ID
Default Sub-net Mask
A
xxx.0.0.1
xxx.255.255.254
255.0.0.0
B
xxx.xxx.0.1
xxx.xxx.255.254
255.255.0.0
C
xxx.xxx.xxx.1
xxx.xxx.xxx.254
255.255.255.0


IP address assigned to the class A network with the number of hosts that are very large. IP Range 1.xxx.xxx.xxx. - 126.xxx.xxx.xxx, there are 16,777,214 (16 million) on the IP address of each class A. In the class A IP address, network ID is the first 8 bits, while the host ID is 24 bits next. Thus, how to read IP address class A, for example, 113.46.5.6 is:
Network ID = 113
Host ID = 46.5.6
IP address on the mean number 46.5.6 host on the network number 113.
Class B IP address is usually allocated to the network medium and large sized. In the class B IP address, network ID is the 16 bit first, while the host ID is 16 bits next. Thus, how to read the class B IP address, for example, 132.92.121.1:
Network ID = 132.92
Host ID = 121.1
IP address on the host means that the number on the 121.1 network number 132.92. With the long 16 bit host ID, the network with the IP address class B can accommodate around 65,000 hosts. IP Range 128.0.xxx.xxx - 191.155.xxx.xxx.
Class C IP address originally used for small-sized network (LAN). Host ID is the last 8 bits. With this configuration, can be formed about 2 million network with each network has 256 IP address. IP Range 192.0.0.xxx - 223.255.255.x.
Allocation of IP address is basically the process of selecting the network ID and host ID is right to a network. Right or not depending on the configuration of this purpose be achieved, which is allocated IP address as efficiently as possible.

7) Domain Name System (DNS)
Domain Name System (DNS) is a system that allows the name of a host computer on the network or the Internet IP address to be ditranslasikan. In giving the name, the DNS hierarchy architecture:
a) Root-level domain: the top level is shown as a dot (.).
b) Top-level domain: category code, or state organizations such as:. com to be used by the company;. edu to be used by universities;. gov for use by government agencies. In addition to distinguish by the name of a country with other countries to use a sign for example. Ps to Indonesia or. Au for australia.
c) Second-level domain: the name for the organization or company, such as microsoft.com, yahoo.com, and others.

8) DHCP (Dynamic Host Configuration Protocol)
IP address and subnet mask can be provided automatically using Dynamic Host Configuration Protocol or filled manually. DHCP function to provide IP address automatically on computers that use TCP / IP. DHCP working relationship with the client-server, where the DHCP server provides the IP address of a group that can be provided in the DHCP client. In providing this IP address, DHCP IP address only lend it. So the IP address this ongoing dynamic.