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.
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.
Benefits from connecting computers together in a network
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...