Computers perform the same basic function: inputting, outputting, processing, and storing data. Also, most computers have the same basic components: input, output, memory, data path, and control. In other words, a computer needs input devices, output devices, storage, and a processor to function.
Liquid Crystal Display (LCD) - A display technology using a thin layer of liquid polymers that can be used to transmit or block light according to whether a charge is applied
Active Matrix Display - A LCD using a transistor to control the transmission of light at each individual pixel
Pixel - the smallest individual picture element. Screens are composed of hundred of thousands to millions organized in a matrix.
While there are a variety of ways to implement a touch screen, many tablets today use capacitive sensing. Since people are electrical conductors, if an insulator like glass is covered with a transparent conductor, touching distorts the electrostatic field of the screen, which results in a change in capacitance or storage of electrical energy. This technology can allow multiple touches simultaneously.
- LCD display
- Headphone jack
- Wi-Fi network
- Bluetooth network
Input and output devices dominate space in a device while data path, control and memory makeup a tiny portion of space.
Integrated Circuits (chips) - A device with dozens to millions of transistors
Central Processing Unit (CPU or processor) - The active part of the computer, which contains the data path and control and which adds numbers, test numbers, signals I/O device to activate, and so on. Data path performs arithmetic operations while control tells the data path, memory, and I/O device what to do according to the instructions of the program
Volatile Memory (Main or primary) - storage for programs and data for programs during runtime
- Dynamic Random Access (DRAM) - A volatile chip that provides random access to any location with an access time of 50 nanoseconds
- Static Random Access (SRAM) - A volatile chip that is faster and less dense than DRAM
- Cache - A volatile, small, fast memory that acts as a buffer for a slower, larger memory
Nonvolatile Memory (Secondary) - hold data and programs between
- Magnetic Disks - Composed of rotating platters coated with a magnetic recording material. Access times are 5 ~ 20 milliseconds
- Flash Memory - Slower and cheaper than DRAM, yet it’s more expensive per bit and more power efficient than disks. Access times are 5 ~ 50 microseconds
Multiple DRAM chips work together to contain the instruction and data of a program.
Abstraction : Hardware and the lowest-level software such instruction set architecture and application binary interface (ABI).
- Communication - Exchange of information between computers at high speeds
- Resource Sharing - Computers on the same network share I/O devices
- Nonlocal Access - Remote access to your computer
With the dramatic rise in deployment of networking and increase in capacity, network technology became an integral part to the information revolution.