Introduction to Computers

What is computer hardware? Hardware refers to the physical components of a computer Chips Circuit boards Electronic storage Monitors, keyboards, speakers, etc. Any part of a computer you can touch and feel is considered hardware

Vital components of a computer Vital components of a computer consist of: Motherboard Processor Memory Storage devices Power supply All the above are found inside the system unit A case that holds the computer’s main components Desktop units designed for users to open the case Notebooks not designed for the case to be opened

The Motherboard A computer’s central or main circuit board Think of it as the electronic hub of a computer All components connect to the motherboard Expansion slots hold additional circuit boards that provide additional functionality such as a sound card. Connections for storage device cables Connector for power supply Heat sink to draw heat away from the processor. Processor is found beneath the heat sink. 2 DIMM slots for memory boards

The Motherboard provides A socket for the processor Slots to insert memory cards Sockets to connect storage devices Expansion slots for additional circuit boards A connection to the power supply Electronic pathways to link all the components

the Processor Executes the instructions found in a program The largest chip on the motherboard Can identify location of processor on motherboard by the heat sink Heat generated by processor is a critical issue Without a means to draw heat away from the processor, it would overheat and eventually fail A heat sink uses metal fins to provide a large exposed surface to dissipate heat A small fan is also often used to draw heat away

Memory Temporary workspace for tasks currently being executed by the processor Think of memory like the surface of your desk Can do more complex tasks with more desk space Can also handle more tasks concurrently Extremely fast access, billionths of a second Both programs and data stored in memory Provided in DIMMs… a board holding a number of memory chips

Storage devices Provide permanent, long-term storage for massive amounts of data Think of a storage device like a file cabinet Data must be retrieved from storage and placed in memory in order for a program to use it Just like data must be moved from a file cabinet to the surface of your desk in order to work with it Relatively slow access, thousandths of a second Types include hard disk, DVD, micro SD, & more

Why both memory & storage devices? Both serve a specific purpose Memory is volatile Must have power to retain data Thus not a good option for long-term storage Storage devices too slow for normal processing Thousandths versus billionths of a second access A factor of a million difference in access time If memory access time were 1 second, storage device access time would be 275 hours.

Storage & memory work together Processor needs data in tiny chunks Memory used to hold these small chunks of data Takes advantage of fast access speed of memory Data in memory must come from storage Data is retrieved from storage in massive chunks Retrieving large amounts of data from storage at one time minimizes slow access time Consider a Word document Entire document retrieved from storage at one time The document is then changed in memory

The Power supply Power comes from an electrical outlet, right? So why does a computer need a power supply? Computers operate on direct current (DC) Electrical outlet uses alternating current (AC) Power supply converts AC from the wall outlet to the DC needed by the computer Power supply fails more than other components If nothing happens when you turn the computer on, the power supply has probably died

Peripheral devices Most peripherals are input/output devices Monitor Keyboard Mouse Printer A microphone, scanner, speakers, and camera are also considered peripheral I/O devices Most peripherals are outside the system unit