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what is a logic gate
A logic gate is an elementary building block of a digital circuit. Complex electronic circuits are built using the basic logic gates. There are 3 basic logic gates: AND, OR, NOT.
The NOT gate
A logical inverter, to differentiate it from other types of electronic inverter devices it has only one input. It reverses the logic state (i.e. its input).
Grace Hopper (1906-1992)
An American computer scientist who, most notably, is given credit for inventing the first computer compiler and helping to popularize machine independent programming. She was also significant in the creation of Flow-matic now COBOL and popularized the term "debugging"(from having to remove actual bugs from the first computers) in CS. She was also one of the first programmers on the Harvard Mark I.
3 Classification according to Types
Analogue, digital, hybrid
2 categories of application software
Application Package and User's Application Program
meaning of ATLAS,PDP, ICL and CDC
Argonne Tandem Linac Accelerator System Programmed Data Processor International Computers Limited Control Data Corporation
what is auxiliary storage
Auxiliary Storage Devices are used for storing information on a long-term basis. Examples are hard disk, flash disk, magnetic tape, memory card,
J. V. Atanasoff The Atanasoff-Berry Computer
By 1941 he and his graduate student, Clifford Berry, had succeeded in building a machine that could solve 29 simultaneous equations with 29 unknowns. This machine was the first to store data as a charge on a capacitor,first to employ binary arithmetic, not programmable, it lacked a conditional branch,was appropriate for only one type of mathematical problem
Hardware is divided into 2
Central Processing Unit (CPU) and the Peripherals.
characteristics of an electronic computer
Electronic in nature - Data are represented in form of electrical pulses. Operation is electronic and basic components are also electronic based integrated circuit (IC). 2. High speed - Computer can perform data processing jobs very fast, usually in the order of microseconds (10-6), nanoseconds (10-9), picoseconds (10-12) or femtoseconds(10-15) depending on the processing power of the computer system used. 3. Accuracy - Accuracy of computer system is consistently high and the degree of its accuracy depends upon its design. Computer errors caused due to incorrect input data or unreliable programs are often referred to as Garbage-In-Garbage-Out (GIGO) 4. Diligence - Computer system is free from monotony, tiredness, and lack of concentration. It can continuously work for hours without creating errors or complaints 5. Automatic control - Once initiated, it could operate on its own, without human intervention, under the control of stored sequences of instructions called program. 6. Flexibility - The computer is capable of doing any task so long the task can be broken down into finite logical steps and it can always be programmed to perform any kind of task.
4 classification of computers
Generations, Types, Size and Usage (or Functions).
Charles Babbage 1792- 1871 analytical difference machine
His objective was to build a program-controlled, mechanical, digital computer incorporating a complete arithmetic unit, store, punched card input and a printing mechanism. Babbage invented the modern postal system, cowcatchers on trains, and the ophthalmoscope,
what is the Jacquard's Loom
In 1801 the Frenchman Joseph Marie Jacquard invented a power loom that could base its weave (and hence the design on the fabric) upon a pattern automatically read from punched wooden cards.
PHILIP EMEAGWALI
In 1989, he invented the formula that used 65,000 separate computer processors to perform 3.1 billion calculations per second. supercomputer and Internet pioneer is regarded as one of the fathers of the internet because he invented an international network which is similar to, but predates that of the Internet. He also discovered mathematical equations that enable the petroleum industry to recover more oil. Emeagwali won the 1989 Gordon Bell Prize, computation's Nobel prize, for inventing a formula that lets computers perform the fastest computations, a work that led to the reinvention of supercomputers.
a computer can be referred to as an
Input Process-Output (IPO) system
Peripherals is divided into
Input devices, Output devices and auxiliary storage devices.
NAND gate
It operates as an AND gate followed by a NOT gate. It acts in the manner of the logical operation "and" followed by negation. The output is "false" if both inputs are "true." Otherwise, the output is "true". It finds the AND of two values and then finds the opposite of the resulting value.
CPU consist of
Main storage, ALU and Control Unit.
Intro to Blaise Pascal
Pascal was born at Clermont, France in 1623 and died in Paris in 1662. Pascal was a Scientist as well as a Philosopher. He started to build his mechanical machine in 1640 to aid his father in calculating taxes. He completed the first model of his machine in 1642 and it was presented to the public in 1645.
what is Software
Software are basically referred to as programs. A program consists of sequence of instructions required to accomplish a well defined task. main categories System software and Application software.
what is System software
System software are programs commonly written by computer manufacturers, which have direct effect on the control, performance and ease of usage of the computer system. Examples are Operating System, Language Translators, Utilities and Service Programs, and Database Management Systems (DBMS)
Functions of alu and control unit
The ALU is the unit for arithmetic and logical operations. The control unit ensures the smooth operation of the other hardware units. It fetches instruction, decode (interprets) the instruction and issues commands to the units responsible for executing the instructions.
what are Utility and service programs
These are programs which provide facilities for performing common computing tasks of a routine nature
what is Preprocessor
This is a language translator that takes a program in one HLL and produces equivalent program in another HLL. For example, there are many preprocessors to map structured version of FORTRAN into conventional FORTRAN.
Describe the human ware
This term refers to the people that work with the computer system it's components in a computer system include the system analyst, the programmer, data entry operator, end user
Full meaning of UNIVAC,ENIAC,EDVAC,EDSAC and IBM
Universal Automatic Computer Electronic Numerical Integrator and Computer Electronic discrete variable automatic computer. Electronic Delay Storage Automatic Calculator, International Business Machines
Bill Gates and Microsoft
William (Bill) H. Gates was born on October 28, 1955, founded a company called Microsoft Corporation (together with Paul G. Allen) He drop out of college so he could concentrate all his time writing programs for Intel 8080 categories of Personal Computers (PC). Microsoft is the largest software manufacturing company in the world.
The NOR gate
a combination of an OR gate followed by an inverter. Its output is "true" if both inputs are "false." Otherwise, the output is "false". It finds the OR of two values and then finds the complement of the resulting value.
what are truth tables
a means of representing the results of a logic function using a table. They are constructed by defining all possible combinations of the inputs to a function in the Boolean algebra, and then calculating the output for each combination in turn. The basic truth table shows the various operators and the result of their operations involving two variables only
what is Data (Singular: Datum)
a piece of basic raw fact, such as a random number or sequence of characters, for example "55" or "Excellence" respectively.
The XOR (exclusive-OR)
acts in the same way as the logical "either/or." The output is "true" if either, but not both, of the inputs are "true." The output is "false" if both inputs are "false" or if both inputs are "true." Another way of looking at this circuit is to observe that the output is 1 if the inputs are different, but 0 if the inputs are the same.
what is Boolean algebra
also referred to as Boolean logic. It was developed by George Boole sometime on the 1840s and is greatly used in computations and in computer operations. The name Boolean comes from the name of the author. Boolean algebra is a logical calculus of truth values. It somewhat resembles the arithmetic algebra of real numbers but with a difference in its operators and operations. Boolean operations involve the set {0,1}, that is, the numbers 0 and 1. Zero [0] represents "false" or "off" and One [1] represents "true" or "on".
what is a computer
an electronic device that accepts data as input, process the data based on a set of predefined instructions called program to produce the result of these operations as output called information.
3 series of operation through which data is transformed into information
arithmetic (such as addition, subtraction, multiplication, and division), logical comparison or character manipulation (as in text processing)
JOHN VON NEUMANN
born on December 28, 1903 in Budapest, Hungary and died in Washington D. C. on February 8, 1957 Neumann with some other people presented a paper titled "The Preliminary discussion of the Logical Design of an Electronic Computing Instrument" popularly known as Von Neumann machine
Howard Aiken The Harvard Mark I computer
built as a partnership between Harvard and IBM in 1944. This was the first programmable digital computer made in the U.S. But it was not a purely electronic computer. Instead the Mark I was constructed out of switches, relays, rotating shafts, and clutches. The machine weighed 5 tons, incorporated 500 miles of wire, was 8 feet tall and 51 feet long, and had a 50ft rotating shaft running its length, turned by a 5 horsepower electric motor. The Mark I ran non-stop for 15 years.
A program is also called
coded instruction
what is software
collection of programs used to solve problems
what is hybrid computer
combine the features of both analogue and digital computers. Found in industrial processes for data acquisition and data processing purposes. need for Analogue-to-Digital Converter and Digital-to-Analogue Converter modulator/demodulator (Modem).
Meaning of Compaq, Vax, TRS
compatibility and quality Virtual Address eXtension Tandy Radio Shack,
what is information
data transformed into a more meaningful and useful form through a defined process
what is an analogue computer
deals with quantities that are continuously varying. It measures changes in current, temperature or pressure and translates these data into electrical pulses for processing. Examples are speedometer, electric meter, water meter, thermometer
what is abacus
digital instrument because it uses beads as counter to calculate in discrete form. It is made of a board that consists of beads that slide on wires. The abacus is divided by a wooden bar or rod into two zones. Perpendiculars to this rod are wires arranged in parallel, each one representing a positional value. Each zone is divided into two levels - upper and lower. Two beads are arranged on each wire in the upper zone, while five beads are arranged on each wire in the lower zone.
second generation computer date component characteristics and examples
early mid-1950's (1955) to late mid-1960's (1964). Transistors reduction in size, less power consumption, generation of less heat and improved storage facility due to introduction of magnetic devices for storage medium and symbolic language. Batch processing operating system and high level languages were also used for programming . They can be used for both scientific and commercial applications. Examples are UNIVAC LARC, ATLAS, IBM 1400 series, PDP 1 & 2 , Honey well 400 etc
First generation computer; date, component , characteristics and examples
early-1940's (1942) to mid-1950's (1955). Vacuum tubes, electromagnetic relay memory, punch-cards secondary storage . Based on machine and assembly languages with stored program concept. enormous heat, consume much electricity, bulky size, highly unreliable, difficult to operate, very expensive to produce commercially and are used mainly for scientific computations. Examples are UNIVAC, ENIAC, EDVAC, EDSAC, IBM 701 etc.
AUGUSTA ADA BYRON
first computer programmer. Ada invented the subroutine and was the first to recognize the importance of looping.
Herman Hollerith 1860-1929
founded a company which merged with two other companies to form the Computing Tabulating Recording Company which in 1924 changed its name to International Business Machine (IBM) . Invented the Punch Card Machine which is also called Hollerith desks.
The AND gate
if 0 is called "false" and 1 is called "true," the gate acts in the same way as the logical "and" operator. The output is "true" when both inputs are "true." Otherwise, the output is "false."
what is operating system
is a collection of program modules which form an interface between the computer hardware and the computer user. Examples are Unix, Linux, Windows, Macintosh, and Disk Operating system.
The XNOR (exclusive-NOR) gate
is a combination of an XOR gate followed by an inverter. Its output is "true" if the inputs are the same, and"false" if the inputs are different. It performs the operation of an XOR gate and then inverts the resulting value.
Describe Database Management System (DBMS)
is a complex program that is used for creation, storage, retrieving, securing and maintenance of a database.
what is a loader
is a program that places an executable object file into memory and makes them ready for execution. Both linker and loader are provided by the operating system.
What is a linker
is a program that takes several object files and libraries as input and produces one executable object file.
what are user's application
is a program written by the user to solve specific problem which is not generalized in nature. Examples include writing a program to find the roots of quadratic equation, payroll application program, and program to compute students' results.
The OR gate
it behaves after the fashion of the logical "or." The output is "true" if either or both of the inputs are "true." If both inputs are "false," then the output is "false."
Fifth generation computers date, component characteristics and examples
late-1980's (1989) still going on . Mimic the intelligence of human expert in a knowledge domain . Implementation of Artificial Intelligence and Expert Systems development. underlining hardware technology is based on Integrated Circuit (IC) using Ultra Large Scale Integration (USLI), large capacity main memory. Software technology include micro-kernel, multi-threading, distributed operating system, multimedia internet application, general purpose machine. Examples are IBM Notebooks, Pentium, SUN, PSAM 10000, and so on.
5 Classifications of computer according to size
mainframe,mini,micro,super, notebook
Fourth generation computers date component characteristics and examples
mid 1970's (1975) to late-1980's (1989). Very Large-Scale Integrated Circuitry (VLSI) in (over hundreds thousand flip-flops were placed in a single silicon chip i.e. thousands of ICs were combined into a single chip. ) Era of microcomputer with introduction of microprocessors, semiconductor memory, hard disks as in-built secondary storage, operating system with Graphical User Interface (GUI) as its major component. Magnetic tapes and floppy disks as portable storage devices were also introduced. Examples include: IBM, COMPAQ 2000 series, Apple II, VAX 9000, TRS-80 etc.
third generation date component characteristics and examples
mid-1960's (1964) to mid-1970's (1975). Integrated Circuitry (IC) (thousands of transistors combined into a single unit component based on SSI (Small Scale Integration) and MSI (Medium Scale Integration). Time Sharing Operating system, multi-programming, Software components were successfully unbundled from the hardware components, use of high level languages. Examples include: IBM 360/370 series, ICL 1900 series, CDC6600 etc.
what is digital computer
operates on data representation in form of discrete values or digits (e.g. 0,1,2,3,X,Y,Z, eg laptops automobile, phones
what is a database
organized collection of related data relevant to the operations of a particular organization. The data are stored usually in a central location and can be accessed by different authorized users.
The advancement in technology over different decades( The industrial revolution during and after the 2nd World War ) did what for the computer industry
serves as a framework for the growth of computer industry and was fully annexed by the stakeholders in Information Technology to fully actualize their dreams of having a very reliable Computer system.
classification according to function
special and general purpose
what is logical comparison
testing whether one data item is greater than, equal to, or less than another item,
what are the three types of data
three types of data - Numeric, Alphabetic, and Alphanumeric
uses of Boolean algebra
to formally describe and define the function of a logic circuit and of one can simplify or reduce the associated hardware