1

CMC: Hardware Unit

  1. How machines communicate with themselves.
  2. Binary system: 0 and 1’s, on/off state (electrical impulses). Why binary? Because Binary systems are the most stable only having 2 states (and thus a wider range of possibilities to define those states (0 – 50 = on and 51 – 100 = off).
  3. Memory: RAM (Random Access Memory) and ROM (Read Only Memory) what Licklidder called indelible memory (RAM) and published memory (ROM). Computers can write to indelible memory (and can revise it but cannot erase it) and read it back forever.
  4. Computer commands are stored in DLL’s (dynamic link libraries).
  5. Command driven. Commands are sent to the processor one at a time (queued). If a processor tries to process 2 or more commands at the same time, then the machine freezes (the blue screen of death) and stops working.
  6. Machine thinking is:
  7. Linear
  8. Sequential
  9. Logical
  10. Ordered/structured
  11. Explicit
  1. How machines communicate with other machines.
  2. The Internet uses client-server architecture.
  3. Servers (machines used to provide services) are linked together using optical fiber cables and routers. Packets of information are sent electronically via the cables. Routers decide where the packets go. Servers can be used for a variety of purposes:
  4. DNS (domain name server): uses the Domain Name System to convert host names such into their IP address such as 145.97.39.155).
  5. IP Address = the unique numerical identifier for every machine on the Internet. You are assigned an IP address when you log into a network using DHCP (dynamic host configuration protocol). Basically, an internet service provider owns a wide range of IP addresses. The DHCP server assigns people IP addresses as they log into the network.
  6. Try this on a PC. Go to “Start”, “Run”. Then type in “command”. In command mode (MS DOD), type in ipconfig /all You should be able to see info about the DHCP server, DNS server, and your IP address.
  7. File server: store files.
  8. Database server: stores databases.
  9. Machines need to have a common language: a protocol.
  10. Protocol (a language or code for formatting and transmitting data) performs the following functions:
  11. How to start and end a message
  12. What to do with a corrupt message
  13. How to deal with a new object or device (handshaking)
  14. Detects connections and connection types
  15. What to do if the connection fails
  16. How to format messages
  17. Machines communicate with each other using different protocols such as:
  18. TCP/IP (transfer control protocol/internet protocol)
  19. HTTP (hypertext transfer protocol)
  20. FTP (file transfer protocol)
  21. POP (post office protocol)
  22. SMTP (simple mail transfer protocol)
  23. IMAP (internet message access protocol)
  24. DHCP (dynamic host configuration protocol)
  25. Client-server architecture: a system of connecting machines using a master/slave relationship or command/request relationship. Clients are used to issue commands. Servers respond to those requests.
  26. Servers do not keep records of the requests made to them (the statelessness of HTTP). You can make the same request over and over and over and the server will not realize it.
  27. To overcome the statelessness of the web, two solutions have been proposed:
  28. Cookies: files stored on the CLIENT that keep records of requests made by the client
  29. Browser cache: web browsers store files on the CLIENT (the “history” feature
  30. Variations of client-server architecture include:
  31. thin clients: the majority of software/hardware is stored on the server. Multiple thin (and fast) clients can use the software/hardware upon request. However, subsequent files are stored on the client.
  32. cloud computing: all functions are stored on the server. All work is done by logging onto the server.
  33. ASP (active server pages): scripts are stored on the server, and help to make webpage content/interface dynamic.
  1. How people communicate with machines
  2. Command driven: type in commands to tell the machine what to do
  3. MS DOS
  4. Unix
  5. Peripheral devices
  6. Mouse: point and click (point the cursor at an icon to start the program) and copy and paste.
  7. Dependent on GUI (graphical user interface).
  8. Has gone through several evolutions. But generally has:
  9. Left click: execute command
  10. Right click: context menu
  11. Tracking ball (for navigation)
  12. Keyboard input.
  13. Using programming languages such as:
  14. Java
  15. Cobalt
  16. Fortran
  17. Using scripting languages such as JavaScript to tell clients or servers what to do when someone does something (such as a mouseover)
  18. Using dynamic scripting languages such as ASP or PHP (PHP preprocessor)
  19. Using codes such as
  20. HTML (hypertext mark-up language): a means for coding Internet documents (this is a header, a paragraph…)
  21. CSS (cascading style sheets): a means for formatting the appearance of Internet documents (this spaces is blue and uses this font)
  22. XHTML (extensible markup language): used for coding web page content [used in database design]
  23. Hyperlinks
  24. Using web browsers such as Internet Explorer or Firefox (GUI’s)
  1. How people communicate with other people via machines (see units on Mobile Technology, Mediated Relationships, Social Networking, Internet Crime, and Business)
  1. How people communicate with themselves via machine (see units on Media Choice and Information Technology)

Machine language (binary numbers, electricity)

Human-Machine Language (programming languages)

Human-human language via machine (human languages)

Human-Computer Symbiosis

  1. How can computers/technology extend human limitations?
  2. Physical limitations
  3. Mobility (distance)
  4. digitally linking people together over vast geographical distances
  5. SKYPE (voip = voice over Internet protocol)
  6. Collaboration (wiki’s, blogs…)
  7. Temporal (time)
  8. synchronous communication
  9. chats
  10. IM’s
  11. Video conferencing
  12. Real time interaction
  13. asynchronous communication
  14. blogs
  15. news groups
  16. websites
  17. 24/7 access
  18. Kinetic (navigation and locomotion)
  19. micekeyboards
  20. GPS
  21. Message construction
  22. One can create written, visual, and oral messages rather easily.
  23. Written
  24. Many options here since the Internet was originally created for text.
  25. Visual (zoom, colors, screen readers…)
  26. GUI’s (graphical user interface)
  27. maximize and minimize
  28. icons
  29. skins
  30. data/knowledge representation (
  31. visualization software
  32. Sound (using subtitles)
  33. sounds for attention
  34. BGM
  35. VOiP (voice over Internet protocol)
  36. video
  37. Mental Limitations
  38. Attention
  39. reminders
  40. nags
  41. notifications
  42. Memory
  43. PIM’s (personal information managers)
  44. Records of everything (written, video, visual, photos)
  45. Information seeking
  46. Information retrieval
  47. Problem Solving/Sense Making
  48. expert systems (
  49. DSS (decision support systems)
  50. data analysis
  51. visual representations of data
  52. Metacognition
  53. rehearsability (I can think about what I say before I say it)
  54. reflection (I can monitor what I say or do because of all the records)
  55. What do computers do well?
  56. Storing vast amounts of data
  57. Calculations
  58. Compiling data together
  59. Detecting things that cannot be seen by the human eye
  60. What do humans do well?
  61. Intuitive understanding
  62. Creation, invention, innovation
  63. Decision making/application