The processor• Integral to all computers is the processor, or central processing unit ( CPU). It is also often referred to as microprocessor. Its role is to process the data entered, following the directions of the software, into the information required.
Two types of memory Read only memory (ROM) Is a permanent internal silicon chip that is inserted before contraction. The programs contained in this memory store can be read and used but cannot be changed altered or erase.
Random access memory (RAM)• Is the temporary memory that is available to the operator to us and manipulate . It stores the operating system and application software while the computer is in use. The contents of RAM are not permanent and are erased when the computer’s power is switched off .
BUS• within the computer. Data is transferred along data lines called buses. The bus is a series of circuits connecting the processor and other parts of the motherboard.• Its purpose is to transfer data within the computer . Buses do not stores and manipulate data.
Mouse, Trackball, Touch pad and Track point • The mouse is almost as common as a keyboard, and is now generally a standard peripheral with most system, a mouse is hand operated and allows the user to move the cursor around the screen. • Trackballs look similar in the upside down mouse placed in the middle of the keyboard.
• Touch pad allows you to simply move your finger over its surface to move the pointer.• A track point has all the features of a mouse in a one small pointer that protrudes from the middle of the laptop keyboard.
BARCODE READER• A barcode is a block of vertical black lines and white spaces, representing an alphanumeric code that identifies the item. The barcode reader needs these codes and produces a series of pulses that corresponds to the barcode.
Types of a barcode• Flat barcode- are commonly used in super markets, as they are more efficient.• Hand held- this are commonly found in departments and hardware stores, where because their products are varying in size and shapes.
• Pen barcode- are generally found in libraries or barrowing outlets such as video shops. Pen readers usually record the barcode of the barrower( normally on a card) and the barcode of the item being barrowed.
SWIPE CARD READER• Swipe card readers electronically read the magnetic strip on the back of the card. The information on the strip is then matched with the personal identification number entered by the cards owner.
SCANNER• Flat-Bed. Drum and hand held scanners are input devices that can take text and image and turn them into digital data. The material can be in a form of text, drawings, or photographs. With the use of software, image can be manipulated and text edited.
TOUCH SCREENS• Another input device that has become popular in environments used by non experts is the touch screen. This allows the user too select he desired option by the ouch of a finger on the screen.