• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The development of the computer - Mainframes, Midrange Computers, Personal Computers, Palmtops (Personal Digital Assistants).

Extracts from this document...

Introduction

Contents Title Page Number Mainframes 2 Midrange Computers 3 Personal Computers 4 Palmtops (Personal Digital Assistants) 5 Glossary Information Technology Coursework Mainframes Mainframes have been around for decades. They were the first systems to power businesses. They often took up extremely large spaces, were expensive to buy and required large amount of power and effort, using water-cooling or air conditioning systems to keep them at optimum temperature. Mainframes are multi-user systems. They allow many users, from hundreds to thousands to work at the same time on different tasks. Mainframes use the CISC instruction set. This stands for Complex Instruction Set Computer. It uses 18 different instruction formats, with system instructions being of variable length, 16bits, 32bits and 48bits. The instructions run directly between memory and the registers, and internally within the registers and the memory. Originally the x86 was had 64kb of RAM which was expandable to 640kb. As there was no hard-drive, data was stored on tapes or 340kb floppy discs. The CPU supported 16bit processing with the use of 16bit registers and 16bit data buses which were internal. Technology has progressed to the point where 64Gigabytes of Physical memory can be used today instead of the 1MB used previously. The processors architecture has also changed. They have expanded in size from a 32bit to a 64bit which means the CPU can now carry out larger data instructions. The Registers have also been upgraded since the x68 was first made available to businesses. ...read more.

Middle

This allows Supervisor access and regular user access to be able to use different functions. This allows security and protection for the system. They are extremely efficient, fast and require less maintenance than Mainframes. They are also able to provide management of networks of PC's and terminals. The disadvantage is that they are not as powerful as mainframes, which means a lot of companies are not interested in them. Personal Computers Personal Computers have overtaken the market with a storm over the past decade to the point where millions of homes have them all over the Globe. They are single user machines with the ability to be networked with other PC's. They currently run with a CPU speed of up to 3 GHz, which are made by the industry spear headers AMD and Pentium. The have an average RAM holding of 256 DDR RAM (Double Data Rate) and a typical Hard Drive space of 60GB. They also contain Cache Memory. This is a storage space that holds data to keep up to speed with the Processor speed. Typical PC registers consist of eight 80bit floating point registers as well as General Purpose registers, in which addresses and data are held. MMX (Multi Media Extension) and SIMD (Single Instruction Multiple Data) was then created by Pentium. This included new Microprocessor instructions to carry out larger instructions involving video, audio and graphical data, as well as being able to use one instruction to perform the same instruction on multiple data items. ...read more.

Conclusion

Glossary CISC (Complex Instruction Set Computer) Computer designed with a full set of instructions that are intended to provide needed capabilities in the most efficient way. RISC (Reduced Instruction Set Computer) RISC enables the microprocessor to run a reduced set of instructions. RISC allows processing at a much higher speed. Static RAM SRAM (static RAM) is random access memory (RAM) that retains data bits in its memory as long as power is being supplied. Flash Memory Flash memory is a constantly powered type of memory that can be erased and reprogrammed in units of memory called blocks. Flash Memory is very popular in Digital Cameras and PDA's to add extra storage capabilities. MMX (Multi Media Extension) MMX adds new Microprocessor instructions to deal with Media such as Video, Audio and Graphics. Allows MMX enabled Processors to run up to 60% more quickly. SIMD (Single Instruction Multiple Data) One of the three performance enhancements of MMX, SIMD lets one instruction within the microprocessor operate at the same time on multiple data items. This is especially productive for applications involving Media such as Video and Audio. FICON (Fiber Connectivity) FICON is a high-speed input/output interface for mainframe computer connections to storage devices. FICON channels increase input/output capacity through the combination of a new architecture and faster physical link rates. ESCON (Enterprise Systems Connection) ESCON is a marketing name for a set of IBM and vendor products that interconnect S/390 computers with each other and with attached storage, attach local workstations with optical fibre technology. 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Computer Science section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Computer Science essays

  1. Marked by a teacher

    The systems development life cycle (SDLC) is a conceptual model used in project management ...

    3 star(s)

    preview' of what the end system will look like and what it will do. This is a very productive process as problems with a design are usually much more obvious when a prototype is created, and can be addressed long before the costly development phase starts.

  2. Peer reviewed

    Principles of Computer Networks

    3 star(s)

    They are a lot less secure. They take a lot of time to maintain the software on an individual workstation. Network performance can be a issue because peer-to-peer is designed for a small network when to a bigger network of let's say 10 or more computers than the network speed will decrease making it difficult to expand.

  1. Computer Architecture

    Here are a few examples of the circuit being carried out. The Red circle/circles show input and Green circle/circles show output data This can be shown in the truth tables below. Task 8 (M4) Provide a description of both astable and bistable flip- flops.

  2. Control Unit, Memory Unit, and Arithmetic Logic Unit. The CPU or Central Processing ...

    A particular type of VDU, called a touchscreen, acts as both an input device and an output device. Information is output by the system onto the screen and the user is invited to answer questions or make choices by pointing at a particular area of the screen.

  1. With diagrams compare and contrast the relative advantages and disadvantages of digital transmission over ...

    e-mails so they need the guarantee of a Service Level Agreement (SLA). This means that should their connection be down longer than the time allowed in the SLA they would receive service credits as compensation. A leased line will give the customer a complete direct connection from their network straight

  2. Storage devices in terms of computers.

    however this can only be reprogrammed a fixed number of times before it wears out. ROM is also non-volatile. Buffering: A buffer is an area of memory used for holding data during input or output transfers to and from input/output devices.

  1. Programming Techniques

    For example by specifying the wrong number or type of parameters in a subroutine call, or tying to assign a real value or a string of characters to a variable which has been declared as an integer e.g Num1 := 'Testing' {Num1 is an integer varaible} * Logic error: the

  2. What is transaction processing?

    processing software are placed on the market, as well as the overall cost of the software and possibility of upgrading the PC. Overall on this application the advantages over weigh the disadvantages and it is felt that this program is an essential item of the business community.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work