ECE 101 An Introduction to Information Technology Computers

Information Path Information Display Information Processor & Transmitter Information Receiver and Processor Source of Information Digital Sensor Transmission Medium

Components in a Simple Computer (Kuc)

Computer Components Memory - contains the instructions and data –segmented into data units, usually 8-bit bytes, with each byte having its own address Instruction Pointer - maintains the memory address of the current instruction Arithmetic Logic Unit (ALU) - processes data in the registers according to the instruction issued by the control unit

Computer Components Registers - quickly and easily accessible memory locations, temporarily store data to be processed by the ALU Flags - 1-bit memories set depending upon the outcome of the just completed arithmetic operations

Components in a Simple Computer (Kuc)

Desktop Computer Hardware Central Processing Unit Memory Storage Input/output

Computer (CPU) Components

CPU - Central Processing Unit Manipulates and controls the flow of data by following the instructions in memory Components include control unit, arithmetic logic unit (ALU), registers, flags and cashe memory (small fast memory to improve the CPU’s efficiency

Moore’s Law as it relates to transistor count in Intel microprocessors. Ref: Turban, Rainer and Potter

Computer Generations (dates approximate) 1 st , vacuum tubes, limited memory and capacity, very large, heating a concern. 2 nd , transistors, less heat and cheaper, more stable and reliable. 3 rd , IC (Integrated Circuits) for storing and processing information. Introduced software that could be used by non-technical people.

Computer Generations (dates approximate) 4 th , VLSI (Very large Scale Integrated Circuits, hundreds of thousands of circuits on a chip, ULSI (Ultra-large scale integration) Late 4 th present, GSI (Grand Scale Integrated Circuit), Over one billion circuits on a chip First four generations used Von Neumann architecture (processing info. sequentially) 5 th - Using Massively parallel processing

Memory RAM - random access memory (read or write data) - volatile (memory lost with no power) MB = 2 20  1 million bytes ROM - read-only memory (reads only previously stored data) - simpler structure and greater capacity. Capacity expanded by DVD-ROM’s with tens of GB’s of data (1 GB = 2 30  1 billion bytes)

Storage Long-term non-volatile retention of data Hard disks accommodate large amounts of data (Giga bytes) but require longer access times (10 msec) than RAM Floppies (now obsolete, 1.44 MB) and ZIP drives (store 100, 250 MB), also “writeable” CD-ROM’s (store up to 650 MB and beyond) Disk on Key (8 to 512 MB (or more) on portable key)

Primary Memory Compared to Secondary Storage Ref: Turban et.al.

Input/Output Input –Keyboard –Mouse –Scanner –Modem Output –Monitor –Soundboard –Printer

Computer Input/Output (Kuc)

I/O Devices Digital I/O port or parallel port - up to 16 binary signals that communicate with digital sensors or controlling devices Analog-to-Digital converter (ADC) Asynchronous communications port (serial port) receives and transmits data through a modem (typically 56bps) Network port - connects through a network interface card (NIC) to high-speed network (> 1 Mbps)

Software Instructions and application programs that permit computers to accomplish tasks As opposed to hardware, software is flexible and easily modified Manipulation of Data –Arithmetic operations (+-*/, + is fundamental) –Logic operations (OR, AND, NOT) –conditional operations (comparative function)

Hierarchy of Software

Software Control of Computers Assembly Language –most basic language (different for each computer type) –typically adding registers or moving data into registers

Software Control of Computers Operating System –set of commands that performs common system tasks, such as accepting data from the keyboard, displaying to the monitor, sending data to the printer –Intel computers commonly used versions of Disk-based Operating System written by Microsoft (MS-DOS) –Graphical user Interfaces (GUI or “gooey”) made computers more user friendly

High-Level Programming Lang. Instructions are more powerful, more general, and better suited for programming a task than the basic assembly language instructions. Some examples: –FORTRAN (FORmula TRANslation) –BASIC –Pascal –C and C+ and C++

Applications Programs Common use of spreadsheets and word processing Packages written by a professional programmer for a specific operating system

Smart Cards Uses a computer to store and process data –Memory card –Microprocessor card Storage on a card without power –ROM is permanent and fixed –Solution: EEPROM - Electrically erasable programmable read-only memory (EEPROM) - use of intense ultraviolet light to reset to 0 (loose all charge)

Simple Smart Card (Kuc)

Smart Cards - Memory Type First Generation –digital memories with 256 bits (32bytes) –information area of 12 bytes for preset info –units area contains the “worth” of the card –all units bits initially 0, spent changes bit to a 1 Second Generation –info area of 8 bytes, control area of 3 bytes –uses 5 “units” counters in base 8 –8 bits per counter each with equal weight

Memory Organization of a 1 st Generation Smart Card

Memory Organization of a 2 nd Generation Smart Card

Refilling a Counter (Kuc)

A set of Counters in a 2 nd Generation memory smart card containing 10,000 units (Kuc)

Microprocessor Smart Cards Advanced smart cards –Does more than store data –Can accept money –complex encryption techniques make money transactions relatively secure –can be contact-less using an antenna around the perimeter of the card

Multiprocessor Computer System Efficient Data Base Searches –Use of many independent computers to complete a task faster –Operate in parallel rather than in series; therefore much quicker Serving Multiple Users –Server ties computers together links them together provides access to share common resources

Multiprocessor Computer Systems