Types and components of computer systems CamilaRodríguez, Senior I B
Index • Hardware and Software • Main components • Memory • Size of memory • Backing storage and Operating systems • User interfaces
Hardware and Software • The parts of the computer you can feel or touch, are called HARDWARE. The computer itself is a hardware, and that’s obvious, but the computer inside your phones, is hardware too. • But the set of instructions that make your computer or mobile phone work is called SOFTWARE. The computer’s OPERATION SYSTEM is essential to keep the computer usable. There’re also APPLICATIONS or PROGRAMMES that allow us to play games or write letters.
Maincomponents Input Device1 Processor (Main memory)2 Output Device3 Storage Device4 1 Input Device: Put data into the computer. 2 Processor: Does something with the data given by the input. 3 Output Device: Tell someone or something the result the processor had came up with. 4 Storage Device: Keeps all this data. If computers didn’t have this, all data will be lose.
Memory • Main memory/ IAS: It stores all the data the computer uses, or what it had produced. It’s electrical, so when it’s switched off, it forgets everything. • ROM (read only memory): Where software are stored, and we cannot change the data of it. • RAM (random access memory): programmes and data being used are stored here. Stores anything that needs to be changed. Is normally much bigger than ROM because it needs to hold more.
Size of memory • Data is stored as a series of 0s and 1s. It’s called bit (Binary digit). • Example: A:10000010 B: 10000011 • 1 byte: 8 bits Fig 1.1
Backing Storage • Storage Device: store programmes when the processor is turned off. • Set of software programs that ‘bring computer to life’. They make the computer do useful things. • There are different types of them, and each of them makes a different function. OperatingSystems FOR YOU TO UNDERSTAND BETTER: If I drive my aunt’s car to go to the shopping, I’m using it to go to the mall or the supermarket, and my aunt may use it to go to work, but it’s the same car used for different things, the same happens with computers, they may look identical, but one person is using it for some thing and the other for another thing.
User Interfaces • Is one program of the operating system. It controls what humans see on the screen. There are different types of interfaces. • Graphical User Interface: it uses graphics to stand for more complicated actions the user wants to carry out. They are typified by the use of icons (Fig 1.2), they can be pointed by an arrow controlled by a mouse. The screen can be divided into areas with different things in them, this is called windows. You put them together and it’s called WIMP. Fig 1.2 Icon.
Command-line interface: interface for communicating with a computer, but you have to type specific commands to tell the computer what to do. Fig 1.3. It’s mostly used by technicians. Fig 1.3
Types of computer and Theirdevelopment • One of the first was invented in the 1940s, by a team of code breakers. They were trying to decode messages sent by German forces during WWII. • In the 1950-60s, the mainframes was invented, it was big but still slow. • in the 1970s people started to fit terminals to mainframes. A terminal is a keyboard and monitor which lets a person have their own connection to the computer.
In the 1980s, these computers were called personal computers (PC’s) because they were controlled, and owned by a person. • In the 1990s portable computers became popular, they are known as laptops (later on notebooks). They have their own power supply and screen. • Netbooks have recently become popular. They are small, cheap and less powerful laptops. Some laptops were small enough to fit in the hand and became known as palmtops. E.g, if a mobile phone has access to the internet it’s call smartphone.