Computer Hardware and Software PDF

# Computer Hardware ## Components of a Computer System - Computer Systems are made up of: - **Hardware** - the physical parts - **Software** - the instructions or programs that control the hardware. - **The Human Being** - the brains behind the whole system! ## Computer Processor (CPU...

# Computer Hardware ## Components of a Computer System - Computer Systems are made up of: - **Hardware** - the physical parts - **Software** - the instructions or programs that control the hardware. - **The Human Being** - the brains behind the whole system! ## Computer Processor (CPU) - The Central Processing Unit (Processor) - Electronic components that process data: - Arithmetic logic unit - Control Unit - Registers - An instruction execution cycle: - Fetch - Decode - Execute - Store - Continues from the moment you power the computer until it's turned off. ## Processor Design Types - RISC and CISC designs - **Reduced Instruction Set Computer** - Uses simple instructions - Operands are assumed to be in processor registers - Not in memory - Simplifies design - Example: Fixed instruction size - **Complex Instruction Set Computer** - Uses complex instructions - Operands can be in registers or memory - Instruction size varies - Typically uses a microprogram ## Computer Memory (1) - **Storage (Memory - Storage Media)** - Electrical components that store instructions and data waiting to be executed by the processor, as well as processing results. - OS software - Application programs - Data - **Memory Types** - Volatile eg. RAM - Non-volatile -> eg. ROM - **Retrieval Methods** - Sequential - Direct ## Computer Memory (2) - **Storage (Memory - Storage Media)** - **Capacity** is the number of bytes a storage medium can hold | Term | Abbreviation | Number of Bytes | Exact Value | | :------- | :----------- | :--------------- | :---------------------------------------------------- | | Kilobyte | KB | 1 thousand | 2¹⁰ or 1,024 | | Megabyte | MB | 1 million | 2²⁰ or 1,048,576 | | Gigabyte | GB | 1 billion | 2³⁰ or 1,073,741,824 | | Terabyte | TB | 1 trillion | 2⁴⁰ or 1,099,511,627,776 | | Petabyte | PB | 1 quadrillion | 2⁵⁰ or 1,125,899,906,842,624 | | Exabyte | EB | 1 quintillion | 2⁶⁰ or 1,152,921,504,606,846,976 | - **Access time** measures the amount of time taken by a storage device to retrieve an item on storage media as well as deliver item from memory to processor. - **Transfer rate** is the speed at which data, instructions and information move to/from a device. # Computer Software ## System Software - Concerned with the computer itself: - devices, file and storage management, error correction - Main piece of SS: Operating System (OS) - OS: the driving program of the computer - Start-up the system - communicates between all programs and the hardware - controls timing and sequence of events - manages data to ensure security and integrity - Manage programs, memory, & system performance - Provide file management - Schedule tasks & configure devices - Control networks - Maintain security - Provide a user interface (UI) - Examples: Windows, Mac OS, Unix ## Functions of an Operating System Software | Function | Description | | :----------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Start Computer** | After a series of checks by the BIOS, the core of the OS (kernel) takes control to allow users to use the system components. | | **Manage Programs, Memory** | Allow multi-tasking, place programs in background or foreground as needed. Allocate data and instructions on KAM as needed for processing. | | **Provide File Management** | Deleting, sorting and renaming files. | | **Schedule Tasks** | Use scheduling algorithm to receive/send data from or to i/o devices, process instructions, transfer items between storage and memory. | | **Configure Devices** | Manages drivers that proper communication takes place with devices and computer. | | **Control Networks** | Coordinates how users share resources and sharing authorizations. | | **Maintain Security** | Define permission of users, stating when and who has access to the computer's resources. | | **Provide User Interface UI** | Three common interlaces are command-line, GUL, and menus-driven interfaces give users control to enter instruction and data. | | **Manage System Performance** | Use utility programs: uninstaller, disk scanners, defragmenters, recovery managers and backup tools... | # Thank You Any questions?