Lecture 2 “Structure of computer” Informatics
Computer is general purpose device that can be programmed to carry out a set of arithmetic or logical operationsprogrammed (Examples: cameras, phones) Two main parts of computer: 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 CPU- Central Processing Unit The brains Performs simple operations e.g. Add two numbers
RAM RAM- Random Access Memory Temporary, working storage bytes RAM is “volatile”, not “persistent”,… gone when power goes out Byte Byte-unit of information storage 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
Persistent Storage: Hard Drive, Flash Drive HARD 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
Computer Software Software –code that runs on the hardware 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)
Windows 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
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