Computer Systems: Hardware, Software, Protocols

Topics Covered

• Components of a computer system including hardware, software, and communication
• Computer systems virtualization
• Protocols and standards

Learning Outcomes

• Describe the basic building blocks of a computer system
• Identify different types of computer systems
• Describe the different protocols and standards in computer systems

Key Terms

• Application Programming Interface (API)
• Arithmetic/Logic Unit (ALU
• Central Processing Unit (CPU)
• Channel (I/O)
• Communication Channel
• Control Unit (CU)
• Distributed Computing
• Embedded Computer
• Graphical User Interface
• Hardware
• Input
• Input-Process Output Model (IPO)
• Interface Unit
• Kernel
• Logical
• Memory
• Modem
• Network Interface Card (NIC)
• Open Computing
• Output
• Port (from one computer to another)
• Primary Storage
• Protocol
• Random Access Memory (RAM)
• Read-Only Memory (ROM)
• Software
• Standards
• Stored Program Concept
• Submit (a job)
• Suite (protocol)
• Virtual
• Von Neumann Architecture
• Word

Importance of Studying Computer Architecture

• Enables understanding of system capabilities and limitations for users
• Allows informed decision-making
• Improves communication with IT professionals
• Aids programmers in creating efficient application software for specific processing needs (compiled versus scripted)
• Helps systems architects/analysts specify computer systems and architecture to meet application requirements.
• Enables intelligent decisions about system strategy (Cost, Quality, & Time).
• Assists system administrators/managers in installing, configuring, maintaining, and upgrading systems
• Maximizes system availability and efficiency
• Optimizes system performance and security
• Enables web services designers to optimize customer accessibility
• Optimizes web system configurations
• Enables selecting appropriate data formats, page designs and scripting languages
• Aids in designing efficient Web pages

The Process Model (IPO)

• Input includes devices like keyboard, mouse, scanner, and punch cards
• Processing is when the CPU executes the computer program
• Output occurs via monitor, printer, and fax machine
• Storage involves hard drives, optical media, diskettes, and magnetic tape

Computer Systems

• Computer systems include at least one CPU
• Memory is needed to hold programs and data
• I/O devices are necessary
• Long-term storage is also needed

Computer System Components

• Hardware processes data by executing instructions, providing input/output, and controlling storage
• Software involves applications and system software that instructs hardware on tasks and order
• Data is the fundamental representation of facts and observations
• Communications allows sharing data and processing among different systems

Hardware Components

• Input/Output devices
• Storage Devices
• CPU includes:
  • ALU (arithmetic/logic unit).
  • CU (control unit)
  • Interface unit
• Memory provides short-term storage for CPU calculations

The Central Processing Unit (CPU)

• ALU: arithmetic/logic unit performs arithmetic and Boolean logical calculations
• CU: control unit controls processing of instructions and movement of data within the CPU
• Interface Unit:
  • Moves instructions and data between the CPU and other hardware components
  • Bus is a bundle of wires that carry signals and power between different components

Memory

• Also known as primary storage, working storage, and RAM (random access memory)
• Consists of bits, each holding a value of either 0 or 1 (8 bits = 1 byte)
• Holds both instructions and data of a computer program, also known as stored program concept

Software Components

• Applications are the software programs to perform tasks
• Operating System includes:
  • API (Application Program Interface).
  • File management
  • I/O
  • Kernel for memory management, resource scheduling, program communication, and security
  • Network Module
• The Bootstrap/Initial Program Load (IPL) stored inside the ROM contains specific instructions to load the OS

Communication Components

• Hardware involves Communication channels
  • Physical connections between computer systems include wire cable, phone lines, fiber optic cable, infrared light, and radio waves
  • Interface hardware is the modem or network interface card (NIC)
• Software establishes connections, controls data flow, and directs data to the proper applications

Virtualization

• Virtualization is existing or resulting in essence or effect though not in actual fact, form or name.
• Virtualization is creating, simulating, or carrying on by means of a computer or network
• Includes virtual memory, virtual networks and Java Virtual Machines

Protocols

• Protocols are common ground rules of communication between computers, I/O devices, and software programs
• Protocols include HTTP (between Web servers and Web browsers), TCP/IP (between computers on the Internet and local area networks), SATA (between storage devices and computers), and new protocols like XML, RSS, and SIP

Standards

• A standard is a document with agreed upon method details
• Standards are created to ensure universal compatibility of data formats and protocols
• Standards may be created by committee or become a de facto standard through popular use
• Standards include computer languages (Java, SQL, C, JavaScript), display standards (Postscript, MPEG-2, JPEG, GIF), character set standards (ASCII, Unicode, EBCDIC), and multimedia standards (MPEG-2, MPEG-4, DivX, MP3)

History

• 1642: Blaise Pascal invents a calculating machine
• 1801: Joseph Marie Jacquard invents a loom that uses punch cards
• 1800's:
  • Charles Babbage attempts to build an analytical engine (mechanical computer)
  • Augusta Ada Byron develops many of the fundamental concepts of programming
  • George Boole invents Boolean logic

History of Modern Computers

• 1937: Mark I is built by Aiken at Harvard University and IBM. First electronic computer using relays
• 1939: ABC is the first fully electronic digital computer. It used vacuum tubes
• 1943-46: ENIAC (Mauchly, Eckert, University of Pennsylvania) it was the first general purpose digital computer
• 1945: Von Neumann architecture is proposed and remains the standard for present day computers
• 1947: Creation of transistor by Bardeen, Shockley, and Brattain at Bell Labs
• 1951-2: EDVAC and IAS

System Software History

• Early computers had no operating systems and were single user systems
• Programs were entered using switches for each bit or by plugging wires into a panel
• 1953-54: First operating system was built by General Motors Research Laboratories for their IBM 701 computer
• Other early systems were FORTRAN Monitor System (FMS), IBSYS and Share Operating System (SOS)

Operating Systems Development

• 1963: Master Control Program (MCP) by Burroughs which included many modern OS features
• 1964: OS/360 by IBM includes batch processing of programs
• 1962: MIT Project MAC created a time-sharing OS called CTSS. Shortly afterwards, MIT, Bell Labs, and GE developed Multics (Multiplexed Information and Computing Services)

UNIX

• After Bell Labs withdrew from the Multics project, Ken Thompson developed a personal operating system called UNIX using assembly language
• Dennis Ritchie developed the programming language C which was used to rewrite much of UNIX in a high-level language
• UNIX introduced a hierarchical file system, the shell concept, document production and formatting, and tools for networked and distributed processing

Graphical User Interface

• 1960s: Doug Englebart (Stanford Research Institute) invented windows and a mouse interface
• 1970s: Xerox PARC created a practical windowing system for the Dynabook project
• 1980s: Steve Jobs (Apple) developed the Apple Lisa and Macintosh

IBM PC

• 1982: Stand-alone, single user computer
• PC-DOS, MS-DOS (disk operating system)
• Later versions of DOS added hierarchical directory file storage, file redirection and better memory management
• Windowing systems occurred like Windows 2.0, Windows 3.1, Windows 95, Windows NT, Windows XP, Windows Vista and Windows 7