Section 4 Xerox PARC Pesented By Magda Attia

Section 4 Xerox PARC Pesented By: Magda Attia

Chapter 4 Contents • The role of Xerox PARC in the development of computer technology • What is bit mapping and how it operates. • What is the meaning of GUI and WYAIWYG • What is a computer network and why do we need it • What is a protocol • What is the Ethernet • Managing the software development process • Types of management structures.

4. 1 Introduction • It is rare for researchers to be given the time and the budget to perform basic research as research does not produce a marketable product • Xerox had made a lot of money from photocopiers by the start of the 1970 s, but the company realized that the photocopier might not be the most important component in the office of the future. Xerox set up a research group at the Palo Alto Research Center (PARC), which attracted a small team of brilliant technologists to research the development of the computer.

Xerox PARC • It can be argued that nearly all the good ideas in computing currently in use can be traced back to PARC, including: 1. graphical user interface (such as the Macintosh and Windows operating systems). 2. Ethernet (a common method of linking PCs together and PCs to printers). 3. object-oriented programming (now the most common method of programming). 4. laser printer.

4. 2 GUIs and WYSIWYG • What-You-See-Is-What-You-Get, or WYSIWYG (pronounced 'whiz-ee-wig') has become one of the dominant ideas in computing. A WYSIWYG system allows you to see a document on screen more or less as it will appear when printed. • Before WYSIWYG, the popular approach was to use 'modes'. If you were creating a document you would use input mode, and then if you wanted to change text you went into edit mode. This made preparing a document a complicated task, because the text displayed on the screen rarely looked like the document you would eventually get from your printer. With WYSIWYG it is possible to manipulate text, graphics and numbers by using a mouse or other pointing device.

The Xerox PARC Alto • For WYSIWYG to be possible it was necessary to have a Graphical User Interface (GUI). • In a Graphical User Interface the cursor can be moved, text can be highlighted, several documents can be opened at the same time, graphics can be drawn, and so on. To do all this the technology of bit-mapping was required. This treats the screen as thousands of picture elements, or pixels. • The first WYSIWYG screens were simply black and white, so each pixel was represented in the computer's memory by a single bit (a binary digit), with the value 1 or 0, corresponding to the pixel being on or off, respectively. If more bits per pixel are used then each pixel could display a colour. • In this way everything could be treated as a graphical element, which allowed greater freedom in manipulation. For example, it is easy to select text and then convert it to italics by altering the appropriate pixels provided that the text is in the form of a bit map.

Bit-mapping • The image on your computer screen is created by the computer specifying the colour of a number of different pixels. • You may have heard people talk about the 'resolution' of a computer display. Typically the sizes values used are 640 x 480, 800 x 600 and 1024 x 768. • These refer to the number of pixels, for example 640 pixels across and 480 down. The process of bitmapping consists of dividing an image up into pixels and then specifying the colour (or grey) value of each pixel.

Bit -Mapping • The process of bit-mapping consists of dividing an image up into pixels and then specifying the Colour (or grey) value of each pixel. • First, the picture needs to be divided up into pixels.

Bit -Mapping Each pixel should be either black or white. If a pixel contains both black and white then the dominant Colour wins. If the pixel is black it is given the value 1, if it is white it is given the value 0 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

bit-mapping • The principles of bit-mapping are used in many applications. • Example, if you send a fax, the fax machine divides up the paper image into pixels and converts it into a stream of bits. These are sent to the receiving fax machine which performs the second half of the process, printing out the image. Even though most faxes have text on them, they are essentially images.

Alto Computer (USD 25, 000) • Alto was the first machine to use GUI. • Alto Never marketed (high cost). • It was seen by a team of people from Apple in 1979, Steve Jobs was so impressed when he saw the Alto, he created the revolutionary Apple Macintosh in its image. • The Alto, built at (and named after) the Xerox (PARC), was the first networked personal computer. Ethernet technology, also invented at PARC, was first used to connect Altos. to explore office automation.

4. 3 Computer Networks Benefits of computer Network: 1. Sharing resources: Sharing HW (printer) &SW (Programs) which Save money and &Installation efforts. 2. Communication: To communicate over l Large geographical distance and use email. 3. File access. Mainframe or minicomputers Store data files and Other computers access them as Airlines and Banking Systems.

4. 3 Computer Networks Types of Networks ( According to shape, topology): 1. 2. 3. Star network. Ring network. Bus Network. Each element on the network, be it a printer, PC, mainframe, or whatever, is referred to as a node on the network. Types of Network ( According to size): 1. 2. 3. - WAN ( Wide Area Network). - LAN ( Local Area Network). - MAN (Metropolitan Area Network)

Star network • arranged in a star shape, with a central or hub computer and several node computers. • The hub computer will control the network, and will often be a mainframe or a minicomputer • Example: The network of automated cash withdrawal machines (ATM) acts in this manner. Each cash withdrawal machine is a node linked to the hub computer, which contains details of bank balances, PIN numbers and so on

Ring network • A ring network is a chain of nodes. • all linked in a circular fashion. • A group of PCs connected to a printer may use a ring network. Or connecting Large-scale computers (mainframe, . . ).

Ethernet A bus network • a single line which connects to each node (stops on a bus route). • Example: PCs and a minicomputer and several printers in a department might use a bus network – Traffic collisions.

4. 3 Ethernet Classification according to their size • WAN (Wide Area Network) • Covers a large geographical area • Each node in a WAN may be located in a different town • A mainframe or minicomputer will usually be involved somewhere in a WAN • Example: A Bank with many branches.

Networks • LAN (Local Area Network) • covers a smaller area than a WAN. • Typically a LAN will serve the needs of one institution at one site • individual bank • LANs often connect to other LANs and to WANs to allow communication between them. These interconnected LANs and WANs form a network of networks commonly known as the Internet • MAN (Metropolitan Area Network): Covers a city

Network Protocols • protocol : shaking hands. The set of rules ensuring the orderly and correct transmission and reception of data in a network is called a protocol. • Data travels over a network is often referred to as 'traffic‘. • Computers in a network cannot just randomly communicate with each other without any rules. • If that was the case then data sent from one computer was to affect data sent from another.

• Example: you can think of data traveling in a computer network as traffic in a highway. If there were no rules followed then there would be many accidents or collisions. As a highway, the network protocol (traffic cop) has to ensure that no collisions occur, but at the same time, it has to allow the data to travel as fast as possible to avoid delays and jams. To ensure that all the nodes in a network follow the same protocol and to correct problems if any, they all should run the same network software that will coordinate the transmission and reception of data. One of the most protocols is called TCP/IP. It is one followed in the Internet.

network protocol • A network protocol must: 1. Allow smooth flow of traffic (no collision) 2. prevent unnecessary blockage or delays. 3. ensure the intelligibility of data to all the nodes. 4. ensure the validity of data (not corrupted). • Examples of network protocols: 1. Ethernet ( invented by Xerox). 2. TCP/IP. (Transmission control protocol/Internet protocl)

Ethernet is a network protocol for LANs. • It operates on a bus network topology. • It was developed by Bob Metcalfe at Xerox PARC. • the most popular method of LAN protocol. • Its popularity is a result of its: – reliability, – speed – relative cheapness. Bob Metcalfe's drawing of the first Ethernet in 1976

How does Ethernet Works? • The Ethernet uses one high-speed cable to connect the different nodes in the network. • When a node sends data through the network, it groups data in units called Packet. • So, before sending a packet to the Ethernet, the controlling network software has to check if any other node is sending another packet. • If so, it has to wait. If the network is not busy then the packet is sent and since we have only one cable the packet is received by everybody.

How does Ethernet Works? • However, only the node that it was addressed to accepts it. • If two nodes at the same time send packets, having both checked at the same time, and there is no traffic in the network at that time a collision occurs. • The Ethernet detects such a collision and makes two nodes wait for a random time (each a different time (usually measured in milliseconds ) and resend the data.

Computers Networks • Examples of network protocols: 1. Ethernet. ( invented by Xerox). 2. TCP/IP. (Used by the Internet)

4. 4 Management in the IT industry • Writing software presents a difficult management problem, because it requires a trade-off between creativity and structured engineering. • it requires strict engineering principles which determine how a particular piece of software code should be written (programmers are often referred to as 'software engineers'). • When producing any large piece of software, for instance a word processing package, a number of different groups will work on different aspects. Group 1 might concentrate on the appearance of the menu bars and buttons on the screen, Group 2 might develop the method by which the program uses the computer's memory, whilst Group 3 is developing a dictionary for use in the word processor. Unless all of these groups are coordinated, their respective components will not work together in the final product.

4. 4 Management in the IT industry • So any management structure in the computer industry is faced with this problem of encouraging creativity. • Conventional management structures are often referred to as vertical. This is because they are hierarchical; the person at the top level of management coordinates the company by communicating with the next level down. Managers at this level in turn communicate with the next level down, and so on. In many companies this communication will be two-way, lower level employees communicating directly with the level above them. Traditionally the amount of power, responsibility and financial reward increases as you go up the hierarchy.

• Vertical Management Horizontal Management

Horizontal management • Vertical Management was deemed to be inadequate for the environment created at PARC by Bob Taylor, because he would have been isolated at the top, and because he wanted to encourage creativity, which often gets stifled in layers of management. • He thus created what is referred to as flat , or horizontal management structure. In this structure there was only one manager, namely Bob Taylor, who coordinated all of the other employees by acting as a communication exchange.

Flat Management • The flat model is not practical for larger organizations, since it relies on one person only being able to act as the sole manager, and beyond about fifty people this becomes difficult (this is why there were only 50 to 70 employees at PARC). • The notion of a horizontal management structure has, been developed in many organizations, particularly in the computing industry. In an organization with a flat structure there are fewer levels of hierarchy. The roles within the organization are also less strict, so employees are encouraged to take on different roles in different projects.

The culture of computer companies • Flat type of management structure and working practice is now being adopted in other industries. • It is also a result of the type of people who founded successful computer companies. Many of these were not traditional entrepreneurs who would have been successful in any business, but rather they were technically minded people who happened to become entrepreneurs. • Many of these founders were very young, and had been influenced by the American hippie culture of the 1960 s - Steve Wozniak and Steve Jobs were still in their early twenties when Apple Computers became a multi-million dollar company.

The culture of computer companies • For example, at the Microsoft campus it is unusual to see someone wearing a tie, soft drinks are free, the buildings have been designed so the maximum number of offices have an external view, programmers are encouraged to make their offices personal (often sleeping in them), and so on. • Many traditional companies would have baulked at the type of person employed in the newer software companies, but these are the people who write good software programs.

Section 5 tuesday IBM & the PC wednsday group

Section 5 Contents • How IBM got into the PC market? • Independent Business Unit. • Open standards and how IBM adopted this standard in manufacturing its PC. • The relation between IBM and Microsoft.

IBM-International Business machines • IBM-International Business machines- is one of the biggest companies in the world. It is famous for its production of a big line of mainframes. • In the computer world they sometimes refer to IBM as the big giant or big blue. Because of its size and power in the computer industry as a whole, other computer companies looked at IBM as the leader in the industry and tried to develop their products according to the direction IBM is taking. • Early involvement of IBM in the PC industry. IBM has a role in the industry and it established industry standards. Then, it got gradual loss of PC market share due to certain factors that will be discussed at the coming slides. • IBM had a huge success producing mainframes, but as we will see later, that success did not translate into another huge success in the PC market.

How IBM starts producing PCs? • In early 1980’s, IBM tried to capitalize on its success in the mainframe world and enter the PC industry. However, IBM was already a huge company with many layers of management. So, to make a decision and act on it took a fairly long time. • The rapid changes and development in the PC industry, especially in the microprocessor side required a different way of operating. • IBM allowed a team of IBM employees to work outside the usual framework of IBM. They formed what is known as the independent business unit (IBU). The objective of this unit or group is to produce an IBM microcomputer (PC) within a year. • The leader of that group was Bill Lowe and was based in a small US city called Boca Raton. The group had a small number of employees and had significant freedom in making decisions.

How IBM starts producing PCs? • The independent business unit (IBU) model was a success and IBM microcomputer was produced within a year. The computer they produced was a huge success and became very dominant in the PC market at that time. • As a result of its success, the IBU method became a widely used method in the PC industry as a whole. • The software giant Microsoft adapted IBU method and the company is divided into many independent units. • Macintosh, another PC produced by Apple, was developed using IBU method.

Industry Standards • Each industry and technology has its own set of standards. As an example you could have a TV from a certain manufacturer and then buy a Video Cassette Recorder (VCR) from a different manufacturer. We take for granted that these machines should work together. • Also in the mobile phone industry you can take a cell phone and travel to another country and still use your phone. This is because the different mobile communication networks in many countries agreed on some standards of communicating. • The PC industry needed also standards. IBM as a leader, fulfilled its role by making its microcomputer a standard for the industry. This was accomplished when the IBU that produced the IBM microcomputer adopted an open architecture.

IBM is an Open Architecture PC • This meant that the parts and components of the IBM microcomputer were often bought from other suppliers and their design was available for anyone else to use. This enabled many companies to produce PCs almost identical in structure to the IBM PC. • IBM kept one piece closed, the BIOS which is the piece that allows the operating system to work with the hardware. So, any company will need to invent its own architecture to work with its own BIOS or use IBM architecture and buy the BIOS from IBM. • Many companies chose to use the IBM architecture and pay IBM for the BIOS. This lead to the beginning of the mass production of PCs and it also allowed IBM to control and dominate the PC industry for a while, but as we will see later, things changed. • Other companies chose to have their own design (different from IBM) and kept it closed. Apple Computer Company is one example. It produced its own machines like Macintosh, which were not compatible with the IBM PC. Apple managed to be successful without having to depend on IBM.

IBM and Microsoft partnership • One of the most important pieces the IBM PC needed was an operating system. At that time the most reliable operating system for PCs was CP/M which stands for Control Program for Microcomputers. A company called Digital Research lead by Gary Kildall made CP/M. IBM tried to contact him to develop a CP/M version for the new PC, but they never met. • IBM contacted with Microsoft, which was a small company. So, instead of using CP/M, IBM agreed to a proposal from Bill Gates to supply the PC with an operating system called MS-DOS was almost identical to CP/M and was even initially obtained from another company, not Microsoft. • Microsoft kept the rights to sell MS-DOS to any other PC manufacturer. That is the main factor that made Microsoft as big as it is today. • IBM and Microsoft partnership was successful and lengthy. Their cooperation continued until the early 1990 s. There were many differences between the way the two companies operate and behave. • Employees from IBM were very formal and tended to do things in a very professional, but sometimes slow, manner. They were used to working in a big corporation with many rules. On the other hand, Microsoft employees were young college graduates who worked in a smart but often unstructured ways. Most of those young Microsoft employees are now big millionaires.

The differences between Microsoft and IBM highlight the differences between the mainframe and the PC industry. Some of the differences are: • Number of customers- The number of customers in the PC industry is much larger than that of mainframe ones. • Sales and Profits- The profit margin in a PC is very small while the profit of selling one mainframe could be hundreds of thousands of dollars. • Customer relation- The relation between a mainframe customer and the dealers continues for a very long time. Some companies still own mainframes that are 20 years old. On the other hand, the relation between a PC dealer and a customer is very short.

Readings And Homework • Read: Section 5 of the course website. • Suggested Reading: Ch 2 section B of the book “Computer Concepts”, in particular page 62. • References: Most of the material in this section is from the course website section 5. • Exercise: In this section you are required to do an exercise that will help you develop information finding skills and get more knowledge about current issues in the computer world. The exercise should also help you to get more comfortable with using the Internet. • you should try to find many magazines and publications that are concerned with computer issues. You can also use the Internet to find online issues of those magazines. The course Website gives some of those online magazines. You should survey as many magazines and publications as possible and then write a list of the four most important computer issues that are being discussed in those publications.