Chapter 2 Introduction to Systems Architecture

Chapter 2 Introduction to Systems Architecture Automated Computation Computer Capabilities Computer Hardware Computer System Classes The Role of Software Economics of System and Application Development Software Computer Networks

History of computing hardware Chapter Goals Discuss the development of automated computing Describe the general capabilities of a computer Describe computer system components and their functions List computer system classes and their distinguishing characteristics Define the role and function of application and system software Describe the economic role of system and application development software Describe the components and functions of computer networks History of computing hardware First Generation (Mechanical / Electromechanical) Calculators Antikythera mechanism, Difference engine, Norden bombsight Programmable Devices Jacquard loom, Analytical engine, Harvard Mark I, Z3 Second Generation (Vacuum Tubes) Atanasoff–Berry Computer, IBM 604, UNIVAC 60, UNIVAC 120 Colossus, ENIAC, Manchester Small-Scale Experimental Machine, EDSAC, Manchester Mark 1, Ferranti Pegasus, Ferranti Mercury, CSIRAC, EDVAC, UNIVAC I, IBM 701, IBM 702, IBM 650, Z22 Third Generation (Discrete transistors and SSI, MSI, LSI Integrated circuits) Mainframes IBM 7090, IBM 7080, IBM System/360, BUNCH Minicomputer PDP-8, PDP-11, IBM System/32, IBM System/36 Fourth Generation (VLSI integrated circuits) VAX, IBM System i 4-bit microcomputer Intel 4004, Intel 4040 8-bit microcomputer Intel 8008, Intel 8080, Motorola 6800, Motorola 6809, MOS Technology 6502, Zilog Z80 16-bit microcomputer Intel 8088, Zilog Z8000, WDC 65816/65802 32-bit microcomputer Intel 80386, Pentium, Motorola 68000, ARM architecture 64-bit microcomputer[32 Alpha, MIPS, PA-RISC, PowerPC, SPARC, x86-64 Embedded computer Intel 8048, Intel 8051 Personal computer Desktop computer, Home computer, Laptop computer, Personal digital assistant (PDA), Portable computer, Tablet PC, Wearable computer Theoretical / experimental Quantum computer, Chemical computer, DNA computing, Optical computer, Spintronics based computer

Systems Architecture Describes structure, interaction, and technology of computer system components Capabilities of a computer Accept numeric inputs Perform computational functions Communicate results

Automated Computation Mechanical Early computers with limited capabilities Electronic Fast, accurate, reliable Optical

Mechanical Implementation Mechanical representation of a mathematical calculation Limitations and shortcomings Complex design and construction Wear, breakdown, and maintenance of parts Limits on operating speed

The Difference Engine 1821 Charles Babbage

Electronic Implementation Stores numerical values as magnetic charges or by positioning electrical switches Can convert physical movement into electrical signals, or vice versa World War II – impetus for change Faster, more reliable, easier to build than mechanical counterparts

Optical Implementation Harnesses energy of a moving photon Represents data as pulses of light stored directly or indirectly by materials that reflect or don’t reflect light Now common in computer networks that cover large distances

Quantum Computing A new kind of computing based on quantum mechanics Somewhat controversial Not yet shown to be usable

Computer Capabilities Processing Storage Communication

Processor Device that performs data manipulation and transformation functions Computation Comparison Data movement memory mass storage input/output devices

Processor Terminology Instructions Programs Processor types General-purpose Special-purpose Formulas and algorithms Comparisons and branching

A Formulaic Program 10 INPUT QUANTITY_SOLD 20 INPUT SELLING_PRICE 30 INTERMEDIATE_RESULT = QUANTITY_SOLD * SELLING_PRICE 40 GROSS_PROFIT = INTERMEDIATE_RESULT – SELLING_EXPENSES 50 OUTPUT GROSS PROFIT 60 END

An Algorithmic Program 10 INPUT INCOME 20 IF INCOME > 7150 THEN GOTO 50 30 TAX = INCOME * 0.10 40 GOTO 180 50 IF INCOME > 29050 THEN GOTO 80 60 TAX = 715.00 + ((INCOME – 7150) * 0.15) 70 GOTO 180 80 IF INCOME > 29050 THEN GOTO 110 90 TAX = 4000.00 + ((INCOME – 29050) * 0.25) 100 GOTO 180 110 IF INCOME > 70350 THEN GOTO 140 120 TAX = 14325.00 + ((INCOME – 70350) * 0.28) 130 GOTO 180 140 IF INCOME > 319100 THEN GOTO 170 150 TAX = 35717.00 + ((INCOME – 146750) * 0.33) 160 GOTO 180 170 TAX = 92592.50 + ((INCOME – 319100) * 0.35) 180 OUTPUT TAX 190 END

Storage Capacity Types of information to be stored Intermediate processing results Data Programs Characteristics of storage devices vary widely Cost Access speed Reliability

Input/Output Capability Must encompass many communication modes For humans: Sound, text, and graphics For other computers: Electronic or optical communication

The Primary Functions of Computer Hardware

Components of a Computer System

Central Processing Unit General-purpose processor Executes all instructions computation functions comparison functions Directs all data movement

Components of The Central Processing Unit

Arithmetic logic unit (ALU) CPU Components Arithmetic logic unit (ALU) Contains electrical circuits that implement each instruction Registers Internal storage locations that can each hold a single instruction or data item Control unit Controls movement of data to and from CPU Accesses program instructions and issues appropriate commands to ALU

System Bus Internal communication channel that connects all other hardware devices Primary pathway for moving data and instructions among hardware components Capacity is critical to performance, secondary storage, and I/O device performance

Primary Storage (Main Memory) Holds program instructions and data for currently executing programs Implemented with random access memory (RAM) Provides access speed and allows CPU to read or write to specific memory locations Volatile; does not provide permanent storage

Secondary Storage Composed of high-capacity nonvolatile storage devices that hold: Programs not currently being executed Data not needed by currently executing programs Data needed by currently executing programs that does not fit within available primary storage

Comparison of Storage Types

Input/Output Devices Implement external communication functions Human-oriented communication devices (e.g., keyboard, mouse, printer) Computer-oriented communication devices (e.g., modem, network interface unit)

Computer System Classes Microcomputer Meets information processing needs of single user Midrange computer Supports many programs and users simultaneously Mainframe Handles information processing needs of large number of users and applications Designed for large amounts of data storage and access Supercomputer Designed for rapid mathematical computation

Multicomputer Configurations Any organization of multiple computers to support a specific set of services or applications Common configurations Cluster Blade Grid

Cluster Group of similar or identical computers that cooperate to provide services or execute a common application Connected by high-speed network Typically located close to one another Advantages: scalability and fault tolerance Disadvantages: complex configuration and administration

Blade Circuit board that contains most of a server computer; a specialized cluster Same advantages and disadvantages as a cluster, but also: Concentrate more computing power in less space Are simpler to modify

Grid Group of dissimilar computer systems, connected by high-speed network, that cooperate to provide services or execute a common application Computers may be in separate rooms, buildings, or continents Computers work cooperatively at some times, independently at others

Bigger Isn’t Always Better Grosch’s Law (1952) has been rewritten due to: Multiple classes of computers Expanded abilities to configure computers for specific purposes Increased software costs relative to hardware costs Large computer databases Widespread adoption of graphical user interfaces Multicomputer configurations

Business Computer Options “Do We Need A Mainframe?” A business finds that its old IBM RS/6000 S70 Midrange computer is overloaded with work. The problem needs to be solved. Options: 1: Purchase more RS/6000 systems, used, since they are no longer made 2: Upgrade to IBM’s latest mainframes, the pSeries 670 or 69 systems 3: Develop a scalable hardware platform IBM blade servers a cluster of IBM midrange systems

The Role of Software Translates user requests into machine instructions Performs complex translation process that bridges two gaps Human language to machine language (binary) High-level abstraction to low-level detail

The Role of Software

Software Types Application programs Stored set of instructions for responding to a specific information-processing tasks Used directly by end users Utility programs Contains instructions for performing general-purpose tasks Usually operates invisibly in the background System software Implements utility functions needed by many application programs Allocates computer resources to application programs Manages computer resources Does not interact with end users

System Layers

System Software Layers

Software/Hardware Layers

Operating Systems Most important system software component Collection of utility programs that provides: Administrative utilities Utility services to application programs Resource allocation functions Direct control over hardware

Operating System Functions Program storage, loading, and execution File manipulation and access Secondary storage management Network and interactive user interfaces

Application Development Software Programs used to develop other programs Types Program translators Program editors Debugging tools System development tools

Economics of System and Application Development Software System software consumes hardware resources Cost per unit of computing power has rapidly decreased Software is more cost-effective when reused many times

The Relative Cost of Hardware vs. Software

Intel CPUs and Microsoft Operating Systems Software Depends on Hardware Once hardware has been developed, the capabilities of the software packages can be increased to take advantage of the hardware capabilities. The development of the Intel microprocessors (from the 80386 to the Itanium) parallels the development of Microsoft Windows and the application software that it supports. This comes from cooperation between Intel and Microsoft.

Computer Networks Set of hardware and software components that enable multiple users and computer systems to share information, software, and hardware resources Enables many types of personal communication

Computer Networks

External Resources Ability to share data, programs, and hardware resources among computers Gives modern organizations flexibility to deploy and redeploy computing and information resources to satisfy rapidly changing needs

Network Software Finds requested resources on the network Negotiates resource access with distant resource allocation software Receives and delivers resources to requesting user or program May also listen for and validate resource requests, and deliver resources via the network

Network Communication and the Physical Network Network communication devices Simpler than I/O devices; do not need to convert data represented electronically into another form Must support communication at high speeds Physical network Complex combination of communication protocols, methods of data transmission, and network hardware devices

Summary Basic elements of computer system architecture Hardware Software Networks Importance of knowing how all components of a computer system interrelate as well as their internal workings Further Readings or Resources: See http://averia.mgt.unm.edu for an up-to-date list of reference materials.

Chapter Goals Discuss the development of automated computing Describe the general capabilities of a computer Describe computer system components and their functions List computer system classes and their distinguishing characteristics Define the role and function of application and system software Describe the economic role of system and application development software Describe the components and functions of computer networks