Lec 3 classification of computers
- 1. Classification of Computers AHSAN ASHFAQ AHSAN ASHFAQ | OMT I | INSTITUTE OF MANAGEMENT SCIENCES PESHAWAR 1
- 2. Classification of Computers Computers are divided into three types on the basis of type of data they process and work on. Digital Computer Analog Computer Hybrid Computer
- 3. Digital Computers Work on digital data. Digital data is the one which is represented by digits/numbers inside the computer system. 0’s and 1’s (Machine language/Binary Language) Any type of data given as input to the computer is converted in to numeric form. Different type of standards are used ASCII
- 4. How a picture is presented in digital form ? Computer breaks down the image into tiny elements called pixels. An image with a resolution of 1024 by 798 pixels has 1024 x 798 pixels (817,152 pixels). each pixel is represented by a binary value. In a monochrome (two color) image, like the example below, just 1 bit is needed to represent each pixel e.g. 0 for white and 1 for black.
- 5. Cont.… In an image that uses 4 colors, 2 bits are needed for each pixel. The following example uses two bits to store the following colors: 00 – White; 01 – Black; 10 – Yellow; 11 – Blue AHSAN ASHFAQ | OMT I | INSTITUTE OF MANAGEMENT SCIENCES PESHAWAR 5
- 6. Analog Computers Work on analog data. Analog data is continuous in nature. Temperature, pressure, speed weight, voltage etc. These quantities are continuous and having an infinite variety of values. It measures continuous changes in some physical quantity e.g. The Speedometer of a car measures speed, the change of temperature is measured by a Thermometer, the weight is measured by Weights machine. These computers are ideal in situations where data can be accepted directly from measuring instrument without having to convert it into numbers or codes.
- 7. Analog vs. Digital From measurement perspective The results of Analog computers are more accurate than the results of Digital computers. From processing perspective The results of digital computers are better than the results of analog computers. Analog computers are faster than digital. Analog computers lack memory whereas digital computers store information. We can say that digital computers count and analog computers measures. AHSAN ASHFAQ | OMT I | INSTITUTE OF MANAGEMENT SCIENCES PESHAWAR 7
- 8. Hybrid Computers Combines the best features of Digital and Analog computers. High speed of analog computer memory and accuracy of digital computer. Can process both continuous (Analog) and discrete (Digital) data. Examples Petrol Pumps ICU analog devices AHSAN ASHFAQ | OMT I | INSTITUTE OF MANAGEMENT SCIENCES PESHAWAR 8