DECIMAL AND BINARY SYSTEMS

DECIMAL AND BINARY SYSTEMS

1. NUMBERS

   • Decimal 0-9
   • Binary (in computers)
     • 0 y 1
       • bits that perform arithmetic with 10 digits
         • numbers from 0-256
           • 8 bits = 1 Byte

2. Byte = 8 bits

   • KB=1024 Bites/1024·8 bits
     • MB=1024 KB/2-20 bytes
       • GB=1024MB/2-30 bytes
         • TB=1024GB/2-40 bytes

3. Storage space required

   • Letter 'a'= 1byte
     • Monday= 6 bytes
       • plain-text email 2KB
         • pixel GIF=12KB
           • 2000 pixel RAW photo 11,4 MB
             • 1min audio file 15MB
               • 3min MP3 audio file=3MB
                 • 1h film compressed= 4GB

4. if you buy a hard disk of 256 GB

   • you install it is of 236 GB
     • its because its calculated in base 1000
       • instead of 1024

5. network

   • 2 or more computers connected
     • physical wireless or both
     • share data and resources
       • Classification
         • size
           • LAN
             • small size
               • owned by organization
                 • computers and devices
           • WAN
             • connect networks in cities or countries
               • biggest-internet
           • MAN
             • whole city
         • Ownership
           • public
             • private (intranets)
               • virtual private networks
         • Realtionship
           • Client-server client request server
             • P2P no responsible server
         • Tipologies
           • Bus all joined to cable
             • Ring all connected. data travells 1 direction
               • Star each one 1 cable connected ro switch/hub (LAN) 5-6

6. Internet

   • Files split in millions odf data p ad sent across the internet.
     • iDifferent routes
       • some info 1 direction and the other the other
         • Packets reassembled
           • wired
             • twisted pair c.n avoid interference
               • Optical fibre transmit data
               • UTP
               • STP
           • Wireless
             • Routers
             • access points
             • reception d
             • Advantages
               • cheap
                 • no specific loc
                   • multiple d
                     • less disruption
               • Disadvantages
                 • interference
                   • connection not stable as wired
                     • lose quality
                       • hacking risk

7. TCP/IP

   • protocol rules connect 2 devices &communicate
     • IP adresses
       • route packets decimal numbers & dots no guarntee reliable delivery
     • TCP
       • make connection reliable
         • no lost, good connection, no duplication delay ok

8. Routing

   • 2 devices= network adress inmediat
     • No connected need router
       • LAN ip gateway WAN public
         • Transfer info & resources from locations
           • Common methodology (Protocol)
             • House w/mailbox =computer w/network
           • Similar to post service

9. TCP/IP services

   • Domain name systems
     • Support internet apps (email,FTP)

10. Comands

    • icpconfig info IP adress & default gateway
      • Ping connectivity 2 devices
        • Tracert find way from fdevice to other