Xerox PARC

Essay by swayerCollege, UndergraduateA+, December 2004

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Module 1

Section 4

4.1 Xerox PARC - Introduction

Other than photocopiers, all the good ideas in computing currently in use can be traced back to PARC, including:

The graphical user interface: such as the Macintosh and Windows operating systems.

Ethernet: a common method of linking PCs together and PCs to printers.

Object-oriented programming: now the most common method of programming.

The laser printer.

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4.2 GUIs and WYSIWYG

Modes: the precursor to WYSISYG. Input mode would be used for creating a document and edit mode for editing. Changing mode made preparing a document complicated because the screen display differed from what you would obtain from your printer.

After modes, there was the use of WYSIWYG

WYSIWYG: 'what you see is what you get' a system that allows you to see on screen more or less what will be printed. A mouse or other pointing device can be used to manipulate text, graphics and numbers.

For WYSIWYG to be possible it was necessary to have a Graphical User Interface

Graphical User Interface (GUI): an interface in which the cursor can be moved, text can be highlighted and several documents opened at the same time.

To do all this, the technology of bit-mapping was required.

Bit-mapping: a technique used to represent images; images are divided into cells and a value is allocated to each cell.

Bit-mapping is used in

Sending a fax.

The Alto: was the first machine to use a GUI.

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4.3 Ethernet

Benefits from connecting computers together in a network

Sharing resources

Communication

File access

Networks can be classified by

1. Topology: The shape of the network's physical structure.

The three main network types

a) Star network: a network arranged in a star shape with a central or hub computer and several node computers. A network of automated...