BMGT301 Introduction to Information to Systems o Bit A binary digit represented by 0 or 1 o Byte 8 bits one byte equals a character o All computers use the binary number system 0 1 o Letters and symbols are represented by 8 bite or 16 bits using o ASCII American Standard Code for Information Interchange Created in 1960 most commonly used before 2008 Based on ordering of English Alphabet 7 bit encoding o Unicode UTF 8 Most common on internet today Variable width 65 000 codes available Multi lingual text o EBCDIC Extended Binary Coded Decimal Interchange Code Most commonly used today in IBM mainframes Non contiguous alphabet 8 bit encoding o If the sort of data is different this will impact reports and online displays of data o Microprocessors typically process 32 or 64 bits at a time o Typical sizes o MP3 5MB o Movie 700 MB o Word document 50 KD o Computer of a Computer o Input Device Used to capture info and commands Keyboard scanner o Output Device Used to see hear etc Monitor printer o Storage Device Used to store info Diskette hard drive CD o Central Processions Unit CPU Actual hardware that interprets and executes the software instructions and coordinates other hardware devices working together o Telecommunications Device Used to send info to and receive it from other locations o Connecting Device Parallel ports that connect a printer to computer etc Modem o Types of memory o Memory Fast storage used for quick acces ROM Read Only Memory Flash Memory No moving parts electric vs mechanical Ex Flash drives memory cards RAM Random Access Memory Used to store instructions and data temporarily during processing Loses data if power is lost Caching Storage of frequently used data Internet explorer Browsing history Virtual Memory Space on hard drive used for swapping in out of RAM o Optical Storage o CD ROM Land Flat Part Reflects light Pit Small scratch scatters light o CD R VS CD RW Write once vs Write many times o DVD ROM Has much smaller lands and pits than a CD o DVD Digital Versatile Disk o Blu Ray Offers more than 5 times the storage capacity of DVDs Better High Definition quality Blu Ray uses a blue laser instead of red which has a shorter wavelength making it possible to focus the laser spot with greater precision Data can be packed more tightly and in less space o Hard Drive o Similar to CD except uses electricity pulses to generate magnetic field to change the polarity of iron particles in the disk coating o Software programs are the instructions that tell computers what to do o Software is written in a computer language which is converted into instructors that a processor can understand o Application software Ex Word Excel Internet Explorer o System Software Microsoft Office Windows Leopard Control primary functions o Interprets the users instructions and turns them into instructions the computer can understand o 1 Memory Management o 2 Process Management o 3 Device Management o 4 Information Management o Networks o Network is the key enabler of IT infrastructure o LAN Local area network o WAN Wide area network o Wireless network o Centralized Processing Work accomplished by one large central computer o Distributed Processing Processing is distributed among multiple computers Client server computing Splits processing between clients and server Peer to peer computing Links computers between internet or network o Internet A global WAN that connects approx 1 million internal computer networks No central control Each computer has as an assigned IP address Ex 135 62 128 91 URL Uniform Resource Locator 1 Protocol http 2 Domain name Web server address www umd edu 3 Document name index html o TCP IP Protocols For two devices to communicate there must be a shared set of rules and procedures for transmitting and interpreting messages protocols TCP IP Transport Control Protocol and Internet Protocol Set of protocols that are the basis for most networks Internet is based on the TCP IP model o Telnet Logging on to one computer system and doing work on another Remote desktop o FTP Transferring files from computer to computer Use FTP software to upload your website files to the web server o World Wide Web A system using HTTP Hypertext Transfer Protocol for storing retrieving formatting and displaying information using a client server architecture URL is the address of a specific resource on the internet o Net Neutrality Prevents internet providers from blocking speeding up or slowing down Web content based on its source ownership or destination
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