1. Chapter 1 Computer Systems

2. Why study Computer Architecture? Examples Web Browsing - how does the browser access pages from a server? How can we create graphics that can be loaded more quickly? Configuring Systems - How good is the system? What kind of performance can one expect for desired applications? What additional information is needed to make a more informed decision?

3. Example - Terminology

4. Java Example Java is best described by a client-server model. Program is compiled on the server into a set of binary code words that represent a generic, stack-based machine language. On the server, the binary code words are interpreted, then executed on a virtual machine. Java uses a multi- threaded paradigm, where new threads are easily created by the programmer.

5. Computer Professional l Deeper understanding of the computer itself - rather than just a user l Understanding inherent operations of a computer promotes effectiveness in its use

6. User l Awareness of the capabilities and limitations of the computer system l An understanding of OS commands and internal operations l Improved communication with others

7. Programmer l Write more efficient programs l Know why some languages are more efficient than others l Understand system errors more clearly l Intermix machine language and higher level language code

8. Systems Analyst l Be able to fix the appropriate system to the application l Supports technical specification of desired system l Learn tradeoffs of different file system formats l Learn requirements for building an internet

9. Important Fact “In an era where technology changes very rapidly, the fundamental architecture of the computer rests on a solid foundation that has changed only slightly and gradually over the last 50 years” - Englander

10. Solid Foundation Has Not Changed l Von Neumann’s Architecture - ‘45 l Unix - late ‘60s l IBM/360 Machine Language - ‘64 identical to today’s IBM/390 l Internet - 25 years old and same protocols and paradigms

11. Computer Application (compare w/WP)

12. Input-Output-Processing-Storage

13. What is Computer Architecture? l Data fundamental representation of facts and observations l Hardware processes data by executing instructions, moves data between storage, input and output l Software instructions executed by the hardware l Communications sharing data and processing among different computers

14. Data Component l Text l Numbers l Pictures l Sound l Video l Animation l Charts Much greater variety in types available today. This component actually has changed in format, but not how it is used. (We will discuss more in Ch 3)

15. A Typical Computer System Hardware

16. Software Component l Systems Software Operating Systems, Utilities l Applications Software fills a business need or solves a business problem

17. An Overview Application Programs Utilities Operating System Computer Hardware End User Programmer O/S Designer

18. Simplified OS Diagram

19. Communications Component l Computers do not operate alone l LAN or WAN l Hardware and Software Components l EQ - communication channels (wire, fiber optics, wireless,…) l EQ - protocols

20. In the Beginning - ENIAC Electronic Numerical Integrator and Calculator Publicly announced in 1946 First operational electronic, general purpose machine Military use 80 ft long, 8.5 ft high, 2 ft wide 18,000 vacuum tubes Programmable

21. Observation Whereas… the ENIAC is equipped with 18,000 vacuum tubes and weighs 30 tons, computers in the future may have 1,000 vacuum tubes and perhaps weigh just 1 1/2 tons. ------ Popular Mechanics, March 1949

22. John von Neumann Principles - 1945 l Stored Program Concept l Binary Processing of Data l Memory is addressed linearly l Memory is addressed without regard to content l Memory holds programs and data

23. Overview of Englander’s Text l Part 1 - Data Number systems, how other forms of data are stored l Part 2 - Hardware CPU, memory, instruction sets, I/O devices, storage devices l Part 3 - Systems Software Operating Systems, User Interface, File Management l Part 4 - Networks and Data Communications