A power supply provides a computer with electrical power in the correct voltage and wattage that it needs.  An AC adaptor will convert Alternating Current (from a standard 120 volt socket) to Direct Current that the system components need.  Desktops typically have a built in power supply that converts AC to DC power. It often has a fan to help cool the computer so it doesn’t overheat and fail.  Notebook computers typically have an AC adapter to convert from AC to DC power, and are also used to re-charge the notebooks battery.  Handheld computers typically are powered by a battery, which can be recharged by an AC adapter.

§          A power supply provides a computer with electrical power in the correct voltage and wattage that it needs.

§          An AC adaptor will convert Alternating Current (from a standard 120 volt socket) to Direct Current that the system components need.

§          Desktops typically have a built in power supply that converts AC to DC power.  It often has a fan to help cool the computer so it doesn’t overheat and fail.

§          Notebook computers typically have an AC adapter to convert from AC to DC power, and are also used to re-charge the notebooks battery.

§          Handheld computers typically are powered by a battery, which can be recharged by an AC adapter.

What are ports? What do they do? Describe four standard ports.

§    A port is a connecting point for external devices to attach to a computer

§    Four standard types include:

o Serial ports: typically 9 pin female ports for connecting a mouse or keyboard

o Parallel ports: typically a 32 pin female port for connecting a printer

o USB ports: newer type for connecting keyboards, printers, etc.

o FireWire ports: newer type to transmit lots of data quickly, typically used to connect digital video cameras to a computer.

Cache memory.

A special high speed memory area, that stores the most recently used data and instructions.

The advantage with cache is it speeds up the processing of data.  The disadvantage is it adds to the cost of the computer.

Flash RAM.

Flash RAM is a special type of memory that is not volatile, but it can be changed.

It is often used for special applications such as in digital cell phones.

Virtual memory.

Virtual memory breaks a program into parts and stores some on a secondary storage device and brings it back into memory when needed.

It helps to expand the ability of a computer to handle larger programs

Name and describe the three types of memory chips.

Memory is high speed electronic storage for a computer.  Three types of memory chips include:

RAM – Random Access Memory – used to hold data and instructions for the active application program.  It is volatile memory, meaning if the power is lost, the contents are also.

ROM – Read Only Memory – used to store permanent System information.  Programs can be “burned in” during the manufacturing process, to provide quick, reliable loading of key features.

CMOS – Complementary Metal Oxide Semiconductor chips are used to store programs that change on occasion, such as the computer’s BIOS – Basic Input Output System.

What are binary coding schemes. Name and describe three.

Binary coding schemes are used to represent characters in a numeric format that can be processed by a digital computer.

ASCII – American Standard Code for Information Interchange – an 8 bit scheme that can represent 2^8^th different characters (256).  It is often used on microcomputers.

EBCDIC – Extended Binary Coded Decimal Interchange Code is also an 8 bit code created by the IBM Corporation, and typically used on mainframe computers

Unicode – a 16 bit encoding scheme that can represent 2^16^th different characters (65,536), therefore it can be used for international languages such as Chinese and Japanese

What are decimal and binary number systems? How are they different?

The decimal number system (base 10) is what people are most familiar with.  It uses ten digits, 0-9, to represent numeric quantities

The binary number system (base 2) is a two digit system, and uses just 0-1 for representing numeric quantities.

The binary system is used to represent how computers process information – most modern computers use a digital or two-state system to represent data and process it.

An example for these systems: the number 13 in decimal is 1101 in binary.

1.     Microprocessors

Research the latest microprocessors from industry leaders such as Intel and AMD.

May recommend that students research the microprocessor industry online, e.g. http://finance.yahoo.com

2.     Processor Serial Numbers

Intel Pentium III microprocessors originally had a unique serial number stamped on it.

What advantages and disadvantages might this cause – think in terms of tracking and privacy issues…

Describe the four basic types of microcomputer system units.

§          Desktop (or Tower) system units: typical computer configuration meant to stay on or near a desk; tends to cost less than other systems with similar power.  Easiest to expand, but lack portability

§          Notebook (or laptop) systems: about the size of a small pizza box, is portable and often as powerful as desktop configurations

§          Tablet PCs: a laptop with a digitized writing surface that will recognize handwriting

§          Handheld computer systems: small, less powerful systems, but they fit in the palm of your hand.  Also know as PDA – Personal Digital Assistants

What is the system unit?

§          The system unit houses the internal electronic components that make up a computer system

§          It is also known as the system cabinet or chassis

§          Some of the main components in it include the motherboard, a power supply, storage drives, and ports to connect external input, communication, and output devices