Module 1, Section 1, Exercise 1.7

What are software and hardware?

• HARDWARE is the physical parts of the computer - monitor, keyboard, mouse, CPU
• SOFTWARE is the programs run on the hardware to make the computer do things

What are the different categories of software?

1. Operating Systems - e.g. DOS, Windows, MacOS, UNIX etc.
2. Languages - e.g. Basic, C, Assembler, Pascal, C++, Visual Basic, Java etc.
3. Applications - e.g. word processors, spreadsheets, databases, graphics apps etc.

What is binary and how does it relates to denary?

Binary is a number system which only has two digits, 0 and 1. Computers operate by turning on and off millions of switches called transistors, for which the states of 'on' and 'off' can be referred to as 1 and 0.

Denary is the number system which runs from 0 through to 10. To convert a number from denary to binary you should think of the binary in terms of a set of columns for which the values are 256, 128, 64, 32, 16, 8, 4, 2, 1. So, for example the denary equivalent of the binary y 11001 = 16+8+1 = 25.

Binary can also be used to represent any letter of the alphabet, or other character. Graphics can also be created with binary through bit-mapping and sound can be divided up into different segments which are each given a binary value, which can then reproduce the sound faithfully.

How does a computer use bits to represent information?

A bit is a binary digit. 8 bits grouped together form a byte - the basic unit which is passed around the computer. Although binary is based on 2 digits, it's important to see how they can be used to represent almost anything, hence are very powerful in helping the computer represent information.

• 1K = 1024bytes
• 1 Meg = 1,048,576 bytes
• 1 Gig = 1000 Meg

By combining a series of bytes any data or instruction can be represented. Some of the earlier programming languages took commands, converted them into 1's & 0's which the computer could then interpret.

What do analogue and digital mean?

Analogue

• continuous signal
• can take any value within their range
• uses physical variables e.g.. voltage, weight, length etc.
• found commonly in nature

Digital

• said to be 'discrete' i.e. separate or distinct
• can only take set values within their range
• often faster and more efficient than analogue
• reliable and easy to manipulate

Analogue to Digital conversion - requires sampling, quantization etc.

What are the main components of a computer and their functions?

• The microprocessor - a chip acting as 'the brains'. Combines the arithmetic and logic unit (ALU) and the control unit and housed on the motherboard
• Clock chip and ROM (read only memory) chip/s share the motherboard
• I/O Devices - Input/Output, such as the keyboard & mouse, monitor & printer.
• RAM - Random Access Memory - chips which store the data being currently used by the computer.
• Hard disk drive - permanent data storage device. Data can also be stored on a CD-ROM, a floppy disk, a zip drive etc.
• Buses - carry data through the computer

What are the factors that affect the power of a computer?

The constraining factors on the power of a computer are the speed of the microprocessor (the more transistors placed upon them, the better the speed of performance), the clock speed (the greater the number of cycles per second, the faster the computer - e.g.. 900Mhz is faster than 233Mhz), the word size (increasing the word size improves complexity and speed, e.g. 128-bit machine will outperform a 32-bit machine) and RAM (an increase in the size of the RAM increases the amount of data the computer can store at any one time)

What is the difference between mainframes, minis, workstations and PCs?

1. MAINFRAMES- Very large, very expensive, powerful computers used by corporates, public authorities, universities etc. for data handling tasks such as file maintenance, simulations involving intensive mathematical work, or for many people to store data upon.
2. MINICOMPUTERS- Powerful, special purpose computers, where 'mini' refers to a small mainframe, not a small PC. Typical uses include plant control, network control and holding large databases.
3. WORKSTATIONS - Powerful PCs using RISC (reduced instruction set computer) chips. Typical uses include CAD, animation, computer simulation and complex multitasking. These machines are typically part of a network.
4. PERSONAL COMPUTER - Microprocessor based machines intended for individual use, with typical applications being for word processing, spreadsheets, DTP, gaming and sometimes acting as servers

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Last updated on Friday, 31-Oct-2003 09:25:39 GMT