Lecture No 10 Extending the Processor’s Power to Other Devices Microcomputer Processors Creating Computer Programs

Extending the Processor’s Power to Other Devices All the components of the computer are tied into CPU by BUS. Can plug the devices into existing Sockets or Ports. If no Ports available then install a board that includes the required ports.

Extending the Processor’s Power to Other Devices Parallel Ports: 25 holes. It transfers 8 bits at a time. Makes Data transfer several times faster than serial ports. Monitor is connected to the system through Parallel port.

Extending the Processor’s Power to Other Devices Serial Ports: 9-25 pins Data bits are transmitted one at a time. PCs come with dedicated serial ports for keyboard and mice. UART (Universal Asynchronous Receiver Transmitter): It converts parallel data from the bus into serial data that flows through serial ports.

Extending the Processor’s Power to Other Devices Specialized expansion ports: - Extends the computer bus to establish links with peripheral devices.

Examples of Specialized Expansion Ports SCSI: (Small Computer System Interface) - 1 card, daisy chain the devices and Fast. USB - connect up to 127 devices, 1 or 2 USB ports. IEEE 1394 (FireWire) - 1 port. Used as standard for plugging video and High data throughput devices. Musical Instrument Digital Interface (MIDI) – Plug in musical instruments. For recording, writing and performing. Lighting, drum machines, synthesizers.

System Expansion When a user wants to have more of memory than the normally used memory or more sound, graphics capabilities than the normal ones, then that can be possible through Add-in Boards or PC cards.

Add-in Boards Add in Boards expand the functions of the system. Card-Like pieces of circuitry that plug into Expansion Slots within the system. These enable the users to add specific types of peripheral devices or expand the capabilities of the system. E.g. Accelerator Board, Fax\Modem Board, Sound Board etc

Plug and Play The Plug and Play standard makes it easier to install hardware via an existing port or expansion slot. Plug in the hardware, OS detects a new components automatically, checks the correct drivers and load the required necessary files.

PC Card Another type of expansion card. Almost the size of a credit card. A PC card fits into a slot on the back or side of the notebook computer to provide new functions. It is used for variety of purposes, can house Disk drives, network cards, memory. Three types: Type I ( To add Memory), Type II ( To add Networking or sound capability), Type III ( Removable Hard drives)

Microcomputer Processors Intel Advanced Micro Devices (AMD) Motorola processors RISC Parallel processing

CPUs Used in Personal Computers – Intel Processors Since 1978, Intel's processors have evolved from the 8086 and the 8088 to the 80286, 80386 and 80486, to the Pentium family of processors. All are part of the 80x86 line. Intel's Pentium family of processors includes the Pentium, Pentium Pro, Pentium with MMX, Pentium II, Pentium III, IV, Celeron, and Xeon processors. The earliest Intel processors included only a few thousand transistors. Today's Pentium processors include 9.5 million transistors or more.

Latest Technology - Intel Speed doubles every 18 months. Pentium 4- up to 3.2 GHz, 50 Million transistors Pentium III /Xeon- up to 2.0 GHz, 50 Million transistors. Celeron- up to 1.8 GHz, 40 Million transistors Itanium- up to 2 GHz, 32 bit. Centrino Mobile Technology.

CPUs Used in Personal Computers – AMD Processors Advanced Micro Devices was long known as a provider of lower-performance processors for use in low-cost computers. With its K6 line of processors, AMD challenged Intel's processors in terms of both price and performance. With the Athlon, AMD broke the 1.0 GHz barrier, claiming the fastest processor title for the first time in IBM-compatible computers.

CPUs Used in Personal Computers – Motorola Processors Motorola makes the CPUs used in Macintosh (680x0) and PowerPC computers. 1) 680x0 family 2) PowerPc Family Macintosh processors use a different basic structural architecture than IBM-compatible PC processors. With the release of the G3 and G4 PowerPC processors, Macintosh computers set new standards for price and performance. New G5, 64-bit.

Apple’s G4 computers are based on Motorola processors

CPUs Used in Personal Computers - RISC Processors Most PCs are based on complex instruction set computing (CISC) chips which contain large 200-300 instruction sets. Reduced Instruction Set Computing (RISC) processors use smaller instruction sets. This enables them to process more instructions per second than (CISC) chips. RISC processors are found in Apple's PowerPC systems, as well as many H/PCs, workstations. Popular in minicomputers (AS/400), and mainframes.

Compaq’s Alpha Server computers are based on RISC processors

CPUs Used in PC’s - Parallel Processing or Symmetric multiprocessing (SMP) In parallel processing, multiple processors are used in a single system, enabling them to share processing tasks. In a Massively Parallel Processor (MPP) system, many processors are used. Some MPP systems utilize thousands of processors simultaneously.

Creating Computer Programs

Computer Program A set of instructions or statements, also called code, to be carried out by the computer’s CPU.

Examples of Common Program Extensions Executable (.EXE) files Dynamic link library (.DLL) files Initialization (.INI) files Help (.HLP) files

Files Typically, a program is stored as a collection of files. Some common file types used in programs are: Executable (.EXE) files actually send commands to the processor. Dynamic Link Library (.DLL) files are partial .EXE files. Initialization (.INI) files contain configuration information for a program. Help (.HLP) files contain information for the user.

Interrupt A preprogrammed set of steps that the CPU follows.

Machine Code Also called machine language. The 1s and 0s that form the language of computer hardware.

Programming Language A Higher-level language than machine language, enables the programmer to describe a program using a variation of basic English.

Source Code File where programming instructions are kept.

Ways to Convert Source Code to Machine Code Compiler – converts a source code program into machine language. Creates an executable file. C++, Java, COBOL, Fortran, Visual Basic Interpreter – translates the code ‘on the fly’. Results immediately. No executable file produced. BASIC, Unix, Perl

Program Control Flow The order in which program statements are executed

How Programs Solve Problems – Program Control Flow The order in which program statements are executed is called program control flow. To determine program control flow, programmers may use a flowchart to map the program's sequence. Programmers may also create a simple text version of a program's code – called pseudo code – to determine how the program will flow.

Flowchart A chart that uses arrows and symbols to show the order in which a program’s statement will run.

Pseudo code Simplified text version of programming code.

Algorithm The steps represented in a flowchart that lead to a desired result are called an algorithm.

Common Flow Patterns To determine when and where to pass program control, a developer may use conditional statements or loops. A conditional statement determines whether a condition is true. If so, control flows to the next part of the program. A loop repeats again and again until a condition is met. Control then passes to another part of the program.

Common Flow Patterns Conditional statement: - A conditional statement determines whether a condition is true. If so, control flows to the next part of the program. Loop: - A loop repeats again and again until a condition is met. Control then passes to another part of the program.

Examples of Loops For While Do-while

How Programs Solve Problems - Variables and Functions A variable is a named placeholder for data that is being processed. Programs contain variables to hold inputs from users. A function is a set of steps that are followed to perform a specific task. By assembling a collection of functions together, a developer can build a complete program.

Structured Programming The practice of building programs using a set of well-defined structures.

Three Control Structures of Structured Programming Sequence structure (flow of the program) – branch Selection structures (if blocks – T/F) Repetition or looping structures (checks a condition – loop repeats while condition is true

Syntax Programming language rules.

Syntax Examples Provide information in a certain order and structure Use special symbols Use punctuation (sometimes)

Three Programming Categories Based on Evolution Machine languages Assembly languages Higher-level languages

Fading Third-Generation Languages FORTRAN (FORmula TRANslator) COBOL (COmmon Business Oriented Language) BASIC (Beginner’s All-Purpose Symbolic Instruction Code) Pascal

Thriving Third-Generation Languages C C++ Java ActiveX

Fourth-Generation Languages (4GLs) Builds programs with a front end, which is an interface that hides much of the program from the user Provides prototypes, which are samples of the finished programs.

Examples of Fourth-Generation Languages Visual Basic (VB) VisualAge Authoring environments

Fifth-Generation Languages (5GLs) Advanced authoring environments considered by some to be 5GLs

World Wide Web Development Languages HyperText Markup Language (HTML) Extensible Markup Language (XML) Wireless Markup Language (WML) Dreamweaver Flash Director