- Explain in general terms how computers store and manipulate
information.
- Describe the basic structure and organization of a computer.
- Discuss the functions and interactions of a computer system’s
principal internal components.
- Explain why a computer typically has different types of
memory and storage devices.
What Computers Do
- Receive input: Accept information from the outside world
- Process information: Perform arithmetic or logical (decision-making) operations on information
- Produce output: Communicate information to the outside world
Store information: Move and store information in memory
Basic Components of a Computer
Input devices :
Keyboards and pointing devices(mouse)
Output devices:
Display or video monitor
Printer
Speakers
Central Processing Unit (CPU)
Memory and storage devices
- Primary storage: RAM (Random Access Memory)
- Secondary storage: Storage devices that serve as long-term repositories for data:
>Hard disk drives
>Recordable CD and DVD drives
>Tape drives
A Bit About Bits
- Every track gives a specific function
- When you press a button it sends through tracks
Decimal Numbers:
- Decimal numbers are 0/1/2/3/4/5/6/7/8/9
- Using two symbols, all numbers can be represented on a calculator as well as performing arithmetic
- Calculator translates the touch on the numeric keypad into series of 0's and 1's
Binary Numbers:
- Represented in 0's (off) and 1's (on)
- Binary denotes all numbers with combination of 2 digits
- Decimals are automatically converted into binary's, vice-versa
- Binary number processing is completely hidden from the user
- Binary's go from right to left
Bits as Codes:
-> ASCII
- Most widely used
- Stands for American Standard code for information interchange
-> Unicode
- Coding scheme that supports 65,000 unique characters
Bits as Instructions in Programs
- Programs are stored as collection of bits
- Program instructions are represented in binary notation through use of codes
Bits, Bytes, & Buzzwords
- Byte = 8 bytes
- Kilobyte (KB) = One thousand bytes
- Megabyte (MB) = One million bytes
- Gigabytes (GB) = One billion bytes
- Terabytes (TB) = One trillion bytes
Green Computing
*The manufacture of hardware and software can have an impact on the environment
- Buy green equipment (energy star)
- Use a notebook & solar battery
- Use energy-saving features
- Turn off the computer when you're away
- Screen savers don't save energy
- Print only once
- Recycle waste products
- Energy costs already exceeds hardware cause
- 20bn kWh a year is wasted die to PCs being left overnight in US & UK
- Power can be saved through server virtualization
-> 2900 servers, 30 mainframes, 80% saving
- Energy efficient coding could cut energy use by up to 30%
- Computers can be both the problem and solution to the problem of being green
- Computers can:
-> Increase business efficiency
-> Enable dematerealization (buying things digitally)
- Intel says computing has saved more resources then it has consumed
Make A Checklist
Plan
-> Buy laptops instead of PC, or thing clients
-> Don't over-specify
-> High-efficiency power unit supply
-> Only green
Maintenance
-> Set monitors off when you leave house
-> Turn off your PC when you leave house
-> Replace CRT monitors with LCDs
Data Centres
-> Highly efficient servers
-> Virtual Servers if possible
-> Review cooling strategies
The computer: The real computer
-> CPU (Microprocessor)
-> Interprets and executes the instructions in each program
-> Supervises arithmetic and logical data manipulations
-> Communicates with all the other parts of the computer system indirectly through memory
-> An extraordinarily complex collection of electronic circuits
-> Houses along with other chips and electronic components on the motherboard
Compatibility
- All software is not necessarily compatible with every computer
- Software written for the powerPC family of processors used in Macintosh computers wont run on Intel processors
- Programs written for Linux cant run on Windows
- CPU's from the same family are generally designed to be backwards compatible
Performance
- Applications require faster machines to produce satisfactory results
- A computer's overall performance is determined by: its internal clock speed and architecture and word size of processor
- Techniques to speed up a computer's performance: parallel processing, server clusters
