











Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
The key points in computer security which should be know as a beginner are given below:Hardware and Software, Physical Parts, Components and Peripherals, Hard Disk, Drive, Motherboard, Execute, Instructions, Microsoft Office, Firefox
Typology: Lecture notes
1 / 19
This page cannot be seen from the preview
Don't miss anything!
(^) Hardware is sometimes referred to as computer components and peripherals. (^) E.g., Motherboard, Hard Disk/Drive
(^) Software is sometimes referred to as programs or applications. (^) E.g., Microsoft Office, Firefox
In early 1800s, Jacquard used punched cards to control a loom.
Hollerith used punched cards for the 1890 US census (his company eventually became IBM!).
Babbage’s difference engine (1830) calculated tables of polynomial values.
Vannevar Bush (1930) built a differential analyzer that used wheels/discs to perform integration.
Babbage designed (but never built) the first general-purpose programmable computer – the analytical engine.
IBM PC (1980) Apple MAC (1985)
(^) This describes how a conceptual computing device works: (^) Memory stores data and instructions. (^) Control Unit (CU) obtains and executes instructions. (^) Arithmetic Logic Unit (ALU) does calculations. (^) Accumulator is internal ALU storage for some data. (^) Input is process of getting data into machine. (^) Output is process of obtaining data from machine.
(^) Most modern computers are Von Neumann machines!
(^) Central Processing Unit (CPU) : microchip that performs core computation. It usually contains the ALU and CU. (^) Memory ( primary storage ): microchips that store data which can be accessed while computer is switched on. (^) Random Access Memory (RAM) is volatile and modifiable. (^) Read-Only Memory (ROM) cannot be changed. (^) Hard drive , Floppy drive ( secondary storage ): store data on magnetic discs permanently i.e., the data is not lost when the computer is switched off. (^) Input/Output devices : transfers data from operator to machine and vice versa.
(^) Operating System : software system that manages resources on computer and executes application programs, e.g., Windows XP, Ubuntu Linux.
(^) II (97), 400MHz (^) III (99) 1GHz (^) IV (2000) 3GHz
(^) The language directly understood by a computer is called machine language. (^) E.g., B4 4C CD 21 terminates a program on a PC (^) Assembly language is a low-level language with mnemonics (codes) used for each instruction to make programming easier for humans. (^) E.g., MOV AH,4Ch INT 21h (^) Low level languages are languages geared towards machines (computers). (^) High-level languages are languages that are easier for humans to use. (^) E.g., Java, C++, Pascal
(^) Programs state explicitly how problem is to be solved. (^) Programs are broken down into named modules of sequential code. (^) e.g., FORTRAN, COBOL
(^) Special case of imperative languages. (^) Real world is modeled as data+actions that can be performed on data. (^) e.g., Java, Smalltalk
(^) Programs state what is to be solved – engine seeks out solution! (^) Programs are stated as rules. (^) e.g., Prolog, XSL
(^) Programs state how problem is solved by applying and composing functions. (^) Programs are stated as functions. (^) e.g., LISP, Mathematica
(^) Operating System (Windows XP, Ubuntu Linux, etc.) (^) Development Tools (Java compiler, Jgrasp, etc.)
(^) Office applications (OpenOffice, MSOffice, etc.) (^) Utilities (Zip, Notepad, etc.) (^) Internet applications (Firefox, IE, etc.) (^) Games (^) ...