History of keyboard

While typewriters are the definitive ancestor of all key-based text entry devices, the computer keyboard as a device for electromechanical data entry and communication derives largely from the utility of two devices: teleprinters (or teletypes) and keypunches. It was through such devices that modern computer keyboards inherited their layouts. As early as the 1870s, teleprinter-like devices were used to simultaneously type and transmit stock markettext data from the keyboard across telegraph lines to stock ticker machinesto be immediately copied and displayed onto ticker tape. The teleprinter, in its more contemporary form, was developed from 1903 to 1910 by American mechanical engineer Charles Krumand his son Howard, with early contributions by electrical engineer Frank Pearne. Earlier models were developed separately by individuals such as Royal Earl Houseand Frederick G. Creed. Earlier, Herman Hollerithdeveloped the first keypunch devices, which soon evolved to include keys for text and number entry akin to normal typewriters by the 1930s. The keyboard on the teleprinter played a strong role in point-to-point and point-to-multipoint communication for most of the 20th century, while the keyboard on the keypunch device played a strong role in data entry and storage for just as long. The development of the earliest computers incorporated electric typewriter keyboards: the development of the ENIACcomputer incorporated a keypunch device as both the input and paper-based output device, while the BINACcomputer also made use of an electromechanically controlled typewriter for both data entry onto magnetic tape (instead of paper) and data output. From the 1940s until the late 1960s, typewriters were the main means of data entry and output for computing, becoming integrated into what were known as computer terminals. Because of the limitations of terminals based upon printed text in comparison to the growth in data storage, processing and transmission, a general move toward video-based computer terminals was affected by the 1970s, starting with the Datapoint 3300in 1967. The keyboard remained the primary, most integrated computer peripheral well into the era of personal computing until the introduction of the mouse as a consumer device in 1984. By this time, text-only user interfaces with sparse graphics gave way to comparatively graphics-rich icons on screen. However, keyboards remain central to human-computer interaction to the present, even as mobile personal computing devices such as smartphonesand tabletsadapt the keyboard as an optional virtual, touchscreen-based means of data entry.

LAN

Alocal area network(LAN) is a computer networkthat interconnects computers within a limited area such as a home, school, computer laboratory, or office building, using network media. [ 1 ]The defining characteristics of LANs, in contrast to wide area networks(WANs), include their smaller geographic area, and non-inclusion of leased telecommunication lines.[ citation needed] ARCNET, Token Ringand other technology standards have been used in the past, but Ethernetover twisted paircabling, and Wi-Fiare the two most common technologies currently used to build LANs.

History of mouse

A computer mouse with the most common standard features: two buttons and a scroll wheel, which can also act as a third button. In computing, amouseis a pointing devicethat detects two-dimensionalmotion relative to a surface. This motion is typically translated into the motion of a pointeron a display, which allows for fine control of a graphical user interface. Physically, a mouse consists of an object held in one's hand, with one or more buttons. Mice often also feature other elements, such as touch surfaces and "wheels", which enable additional control and dimensional input. Naming The earliest known publication of the termmouseas a computer pointing device is in Bill English's1965 publication "Computer-Aided Display Control". [ 1 ] The onlineOxford Dictionariesentry formousestates the plural for the small rodent ismice, while the plural for the small computer connected device is eithermiceormouses. However, in the use section of the entry it states that the more common plural ismice, and that the first recorded use of the term in the plural ismiceas well [ 2 ](though it cites a 1984 use ofmicewhen there were actually several earlier ones, such as J. C. R. Licklider's "The Computer as a Communication Device" of 1968 [ 3 ]). According to the fifth edition of The American Heritage Dictionary of the English Languagethe plural can be either "mice" or "mouses".

history of hard disk

In 1953 IBMrecognized the immediate application for what it termed a "Random Access File" having high capacity and rapid random access at a relatively low cost. [ 1 ]After considering technologies such as wire matrices, rod arrays, drums, drum arrays, etc., [ 1 ]the engineers at IBM's San Jose California laboratory invented the hard disk drive. [ 2 ]The disk drive created a new level in the computer data hierarchy, then termed Random Access Storage but today known as secondary storage, less expensive and slower than main memory(then typically drums) but faster and more expensive than tape drives. [ 3 ] The commercial usage ofhard disk drivesbegan in 1956 with the shipment of an IBM 305 RAMACsystem including IBM Model 350 disk storage. [ 4 ] US Patent 3,503,060issued March 24, 1970, and arising from the IBM RAMAC program is generally considered to be the fundamental patent for disk drives. [ 5 ] Each generation of disk drives replaced larger, more sensitive and more cumbersome devices. The earliest drives were usable only in the protected environment of a data center. Later generations progressively reached factories, offices and homes, eventually reaching ubiquity. Disk media diameterwas nominally 8 or 14 inches (200 or 360 mm) and were typically mounted in standalone boxes (resembling washing machines) or large equipment rack enclosures. Individual drives often required high-current ACpower due to the large motors required to spin the large disks. Hard disk drives were not commonly used with microcomputers until after 1980, when Seagate Technologyintroduced the ST-506, the first 5.25 inches (133 mm) drive. The capacity of hard drives has grown exponentially over time. When hard drives became available for personal computers, they offered 5- megabytecapacity. During the mid-1990s the typical hard disk drive for a PC had a capacity of about 1 gigabyte. [ 6 ]As of January 2012, desktop hard disk drives typically had a capacity of 500 to 2000 gigabytes, while the largest-capacity drives were 4 terabytes.

Basic hardware troubleshooting techniques

There are many devices, parts, cords, and connections on a computer, which means there are many possible problems that could arise. In addition, your computer uses a variety of software, which can also cause problems. However, no matter what the problem is, you can use thefollowing tipsto help you find a solution: Always check the cables:Many computer problems are related to an issue with the cables and connections. The easiest first step you can take to troubleshoot most problems is to check all related cables and connections. Isolate the problem:If possible, try to isolate the problem. For example, if you can't get the cursor to move on the screen, try to determine if the issue is with the mouse. If you have an extra mouse, you can alternate devices to see if the one plugged in is the issue, or use the arrow keys on the keyboard to help determine if the mouse is the source of the problem. When trying to isolate the problem, only make one change at a time. Take notes about error messages:If your computer gives youerror messages, be sure to write down as much information as possible. If the basic troubleshooting steps don't work, you may need the information. Remember the steps you've taken, or write them down:Once you start troubleshooting, you will want to remember what you have done so you don't repeat yourself. If you can't remember it, write it down. If you end up asking people for help, it will be much easier if they know exactly which steps you've taken.

Bluetooth

Bluetooth / Personal Area Network Bluetooth - Wireless Done Better Bluetooth gives your PC, Laptop, Cell Phone or other device an edge when it comes to wireless devices. Bluetooth keyboards and miceprovide a superior input experience without all those messy wires, while a bluetooth headset can make your calls easier and make your music / gaming experience more enjoyable. Bluetooth adapters add bluetooth support to any standard PC so that you can sync your phone or use a bluetooth keyboard, bluetooth mouse, or bluetooth headset.

Ms access vs Oracle

Microsoft Access, also known as Microsoft Office Access, is a database management system from Microsoft that combines the relational Microsoft Jet Database Engine with a graphical user interface and software-development tools. It is a member of the Microsoft Office suite of applications, included in the Professional and higher editions or sold separately. Microsoft Access stores data in its own format based on the Access Jet Database Engine. It can also import or link directly to data stored in other applications and databases.[1] Software developers and data architects can use Microsoft Access to develop application software, and "power users" can use it to build software applications. Like other Office applications, Access is supported by Visual Basic for Applications, an object-oriented programming language. Oracle Database (commonly referred to as Oracle RDBMS or simply as Oracle) is an object-relational database management system produced and marketed by Oracle Corporation. The Oracle RDBMS stores data logically in the form of tablespaces and physically in the form of data files. Table spaces can contain various types of memory segments, such as Data Segments, Index Segments, etc. Segments in turn comprise one or more extents. Extents comprise groups of contiguous data blocks. Data blocks form the basic units of data storage. A DBA can impose maximum quotas on storage per user within each table space. Oracle, MS Access, and any other vendor's database package all have their advantages and disadvantages. Selecting one over another is really a case of weighing the advantages and disadvantages for your specific case. MS Access - This package is very cheap (it is part of Office Professional) and very easy to use. Most of the work in Access is done through wizards and GUI tools. One can quickly develop a small, single user database with this one. MS Access is not very good for a multi-user application. It is not very robust and does not have good multi-user transactional control. In addition, Access cannot handle large amounts of data. All of the data in the database is stored in a single file and that has its limitations.MS Access is a small database with limited database functionality following 7-8 CODES rule of perfect database. Oracle - This package is not cheap at all. It is very complex and it can be difficult to administer. But its complexity makes it very robust. There is almost nothing that you cannot do in Oracle (unlike Access). Oracle is specifically designed for multi-user applications. In fact, thousands of users can access the same data without any problems due to Oracle's very good transactional control. But applications are not developed nearly as quickly. Oracle can also handle large amounts of data. In fact, Oracle 8i can handle up to 512 petabytes of data! Oracle provides more security than access. It can handle much more complicated databases. Oracle is a closest of being a perfect RDBMS. Oracle is based on client server approach and must be installed to host application. Oracle is a server based database. In the end, Oracle is a true Database Management System (DBMS) and Access is not. This does not mean that Access does not have its place. If you are designing a quick database that only you will use, you can do it in Access over Oracle. If you are designing a robust, scalable application used by many users, then Oracle is the better choice!

Insertion of RAM

Different types of Ram are not supported on same system at a time Eg:; ddr1 and ddr3 model ram are not used in a system at a time.

RANDOM ACCESS MEMORY (RAM)

Random-access memory(RAM / r æ m /) is a form of computer data storage. A random-access memory device allows dataitems to be read and written in roughly the same amount of time regardless of the order in which data items are accessed. [ 1 ]In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWsand the older drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement delays. Today, random-access memory takes the form of integrated circuits. Strictly speaking, modern types of DRAMare not random access, as data is read in bursts, although the name DRAM / RAM has stuck. However, many types of SRAMare still random accesseven in a strict sense. RAM is normally associated with volatiletypes of memory (such as DRAM memory modules), where stored information is lost if the power is removed, although many efforts have been made to develop non-volatile RAM chips. [ 2 ]Other types of non-volatile memory exist that allow random access for read operations, but either do not allow write operations or have limitations on them. These include most types of ROM and a type of flash memory called NOR-Flash. Integrated-circuit RAM chips came into the market in the late 1960s, with the first commercially available DRAM chip, the Intel 1103, introduced in October 1970.