personal computers system
personal computers system
PRICE RM 2131.00
An Intel 80486DX2 CPU, as seen from above
Bottom side of an Intel 80486DX2, showing its pins
A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions. The computer industry has used the term "central processing unit" at least since the early 1960s. Traditionally, the term "CPU" refers to a processor, more specifically to its processing unit and control unit (CU), distinguishing these core elements of a computer from external components such as main memory and I/O circuitry
CPU is a very complex device with a highly large set of electronic circuitry. A processor is used to execute a stored program instruction which is given to it by the user through input. Every type of computer whether it is small or large must have a processor in them.
The computer is a very fast machine. A normal desktop computer can execute an instruction in a less than 1/millionth of a second whereas a supercomputer (which is fastest of all the computers) can execute an instruction in less than 1/billionth of a second!
CPU speed of executing an instruction depends on its clock frequency which is measured in MHz (megahertz) or GHz (gigahertz), more the clock frequency, more is the speed of computer’s instruction execution.
A USB port is a standard cable connection interface for personal computers and consumer electronics devices. USB stands for Universal Serial Bus, an industry standard for short-distance digital data communications. USB ports allow USB devices to be connected to each other with and transfer digital data over USB cables. They can also supply electric power across the cable to devices that need it.
Desktop computer -
A desktop computer usually has two to four ports in the front and two to eight ports in the back.
Laptop computer -
A laptop computer has between one and four ports on the left, right, or both sides of the laptop.
- The USB connection on a tablet is located in the charging port and is usually micro USB and sometimes USB-C. Some tablets have additional ports USB ports.
Similar to tablets, the USB port on smartphones is used for both charging and data transfer in the form of USB-C or micro USB.
iPod or other MP3 player
Jump drive aka Thumb drive
An asynchronous port on the computer used to connect a serial device to the computer and capable of transmitting one bit at a time. Serial ports are typically identified on IBM compatible computers as COM (communications) ports. For example, a mouse might be connected to COM1 and a modem to COM2. The picture shows the DB9 serial port on the back of a computer.
- One of the most commonly used devices for serial ports, usually used with computers with no PS/2 or USB ports and specialty mice.
- Another commonly used device for serial ports. Used commonly with older computers, however, is also commonly used for its ease of use.
- One of the original uses of the serial port, which allowed two computers to connect together and allow large files to be transferred between the two.
- Today, this not a commonly used device for serial ports. However, was frequently used with older printers and plotters.
Less commonly referred to as the Centronics interface or Centronics connector after the company that originally designed it, the port was later developed by Epson. The parallel port is found on the back of IBM compatible computers and is a 25-pin (type DB-25) computer interface commonly used to connect printers to the computer
- The most common use for the parallel port.
- Another commonly used parallel device is a parallel port scanner. Parallel port scanners are a popular alternative to SCSI scanners because of how easy they are to install.
- Another popular use of the parallel ports are external drives such as the Iomega Zip Drive, which can be removed from one computer and placed onto another.
Ethernet is a family of computer networking technologies commonly used in local area networks (LANs) and metropolitan area networks (MANs). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3, and has since been refined to support higher bit rates and longer link distances. Over time, Ethernet has largely replaced competing wired LAN technologies such as token ring, FDDI and ARCNET.
Since its commercial release, Ethernet has retained a good degree of backward compatibility. Features such as the 48-bit MAC address and Ethernet frame format have influenced other networking protocols. The primary alternative for some uses of contemporary LANs is Wi-Fi, a wireless protocol standardized as IEEE 802.11.
Systems communicating over Ethernet divide a stream of data into shorter pieces called frames. Each frame contains source and destination addresses, and error-checking data so that damaged frames can be detected and discarded; most often, higher-layer protocols trigger retransmission of lost frames. As per the OSI model, Ethernet provides services up to and including the data link layer.
The original 10BASE5 Ethernet uses coaxial cable as a shared medium, while the newer Ethernet variants use twisted pair and fiber optic links in conjunction with hubs or switches. Over the course of its history, Ethernet data transfer rates have been increased from the original 2.94 megabits per second (Mbit/s) to the latest 400 gigabits per second (Gbit/s). The Ethernet standards comprise several wiring and signaling variants of the OSI physical layer in use with Ethernet.
The Video Graphics Array (VGA) is one of the oldest connection standards which can still be found in large swaths of computing equipment. It was first developed by IBM and introduced in 1987. It was widely used for video cards, TV sets, computer monitors, and laptops .
The VGA cable can carry RGBHV video signals: Red, Green, Blue, Horizontal Sync, and Vertical Sync. The VGA socket is made up of 15 pins in three rows of five pins, and typically colored blue. The cable socket is securely attached to the device using two screws, one on each side of the socket.
What does a VGA connection do?
A VGA connector on your AV equipment is normally there for you to connect your PC or laptop.
This connection type will usually be designed to receive an analog RGB signal from a connected device - which is the type of signal that you get from a computer. It supports standard-definition and high-definition resolutions.
It does not transmit audio signals and so a separate audio connection will be required to hear any audio.
The standard 15-pin D-Sub connector is common on many computers, and therefore you can use VGA to VGA cables to send a computer image to your TV screen.
External connector, similar to a USB port, that provides a high-speed connection between a computer and peripheral devices. Firewire was developed by Apple, Inc. and is based off the standard IEEE 1394 high performance serial bus. Firewire ports are able to transfer data at a rate of up to 400 Mbps. This technology was once standard on computers manufactured by Apple, Inc., but has since been replaced by Thunderbolt ports and later versions of USB ports.
FireWire connections are easy to distinguish from USB because they are smaller and tapered on one end, while USB is flat and rectangular. As said above, FireWire is most commonly found on audio and video devices like digital camcorders. It’s also common to find FireWire on external storage devices. The main reason to use FireWire over USB is simply the connection speed. If you have a device that supports both FireWire and USB, you’re better off using the FireWire option – unless your device supports USB 3.0. I’ll explain more about that in a second.
A graphics card is a set of computer chips on a circuit board roughly the size of an index card. The chips are dedicated to a single task: to take video data from the PC's processor and convert it to signals for your monitor. Though most computers have graphics chips built into the motherboard, their capabilities are usually basic. Graphic designers, gamers and multimedia enthusiasts typically purchase more sophisticated graphics cards; these plug into the motherboard and deliver faster graphics processing and better image quality
PRICE RM 299
A hard disk drive (HDD), hard disk, hard drive or fixed disk[b] is an electromechanical data storage device that uses magnetic storage to store and retrieve digital information using one or more rigid rapidly rotating disks (platters) coated with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored or retrieved in any order and not only sequentially. HDDs are a type of non-volatile storage, retaining stored data even when powered off.
price RM 488.00
Optical disc drives are an integral part of standalone appliances such as CD players, DVD players, Blu-ray disc players, DVD recorders, certain desktop video game consoles, such as Sony PlayStation 4, Microsoft Xbox One, Nintendo Wii U, and Sony PlayStation 3, and certain portable video game consoles, such as Sony PlayStation Portable. They are also very commonly used in computers to read software and consumer media distributed on disc, and to record discs for archival and data exchange purposes. Floppy disk drives, with capacity of 1.44 MB, have been made obsolete: optical media are cheap and have vastly higher capacity to handle the large files used since the days of floppy discs, and the vast majority of computers and much consumer entertainment hardware have optical writers. USB flash drives, high-capacity, small, and inexpensive, are suitable where read/write capability is required
PRICE RM 459.00
What is the parallel port used for?
Where are the USB ports?
PRICE RM 40.26