Computer Appreciation Chapter 1

Study Notes

A computer is an electronic machine that processes user input into useful information.
It can accept various forms of input, including data, programs, and user replies.
Known as data processing units or data processors, computers operate under stored instructions.
Data refers to raw details that must be processed to create informative content.
Programs are sets of instructions executed by a computer, either sequentially or non-sequentially.
User replies are the responses given by users to queries posed by the computer.
The information processing cycle includes input, processing, output, and storage activities.
Effective communication is integral to the information processing cycle.

Software is a collection of related instructions organized for a specific purpose.

Speed: Capable of solving complex problems in seconds; speed is influenced by hardware configuration.
Storage Capacity: Can store large amounts of data, divided into main memory and secondary storage.
Accuracy: Performs calculations with high precision, reliant on hardware and instruction quality.
Reliability: Produces results free from errors, with user error often being the cause of mistakes.
Versatility: Able to perform various tasks across different applications.
Diligence: Can execute repetitive calculations consistently without human traits like fatigue.
Garbage-In, Garbage-Out (GIGO): Computers can only output what they are programmed to do.

The input unit is responsible for entering data into the computer.
Functions include accepting instructions and data, converting them into machine-readable form, and supplying them for further processing.

The output unit displays information generated by the computer to the user.
Functions involve accepting coded results, converting them into a human-readable form, and delivering these results externally.

Responsible for storing data and instructions, intermediate results, and final results before output.
Primary Storage (Main Memory/RAM):
- Holds running program instructions.
- Fast but has a small capacity and is volatile.
Secondary Storage (ROM):
- Holds stored program instructions and job data.
- Slower but has a larger capacity and retains data without power.

The CPU is the central component of a computer system, often termed the "brain."
Responsible for data processing and controlling other components in the system.
Main CPU operations include fetching, decoding, executing instructions, and storing results.
Comprised of two main subsystems:
- Arithmetic Logic Unit (ALU): Executes actual instructions.
  - Arithmetic Unit (AU): Specifically handles arithmetic operations such as addition and subtraction.