Transcript Lecture 2
Lecture 2 “Structure of computer” Informatics general purpose device that can be programmed to carry out a set of arithmetic or logical operations (Examples: cameras, phones) Two main parts of computer: Computer is Hardware refers to the physical parts of the computer Example: piano is a harware Software refers to the code that runs on the computer Example: the music is the sofware Computer Hardware There are 3 major parts that make up computer: CPU RAM Persistent Storage CPU- Central Processing Unit CPU The brains Performs simple operations e.g. Add two numbers RAM Byte Byte-unit of information storage RAM RAM- Random Access Memory Temporary, working storage bytes RAM is “volatile”, not “persistent”,… gone when power goes out All measured in bytes, despite being very different hardware 1 byte is enough to hold 1 letter Kilobyte, KB, about 1 thousand bytes Megabyte, MB, about 1 million bytes Gigabyte, GB, about 1 billion bytes HARD DRIVE Persistent Storage: Hard Drive, Flash Drive Stores bytes as a magnetic pattern on a spinning disk FLASH DRIVE Stores bytes as electrons in a chip e.g. usb key, SD card in camera, flash chips built into a phone or tablet Software –code that runs on the hardware Computer Software Software is machine code CPU implements “machine code” instructions Operating System Operating system is set of supervisory programs, run when computer first starts Starting/managing/ending other programs Modern operating systems: functions ● Program execution ● Memory management ● Multitasking ● Disk access and file systems ● Networking ● Security Operating Systems There are three main families of operating systems: Linux Windows MacOS Linux • Fedora, Ubuntu, RedHat, Suse • mostly free • mostly open-source (customizable) • Most widespread operating system • Windows 3.1, Windows 98, Windows ME, Windows XP, Windows Vista, Windows 7, Windows 8 • Operating system is a property of Microsoft Windows MacOS • bundled in Mac computers • cannot work with other computers • well-known for its’ pretty and intuitive user interface Drivers A device driver or software driver is a computer program allowing OS to interact with a hardware device