1. CT Seeram Chapter 2: Introduction to Computers

2. Electronic Computer Technology Vacuum tubes Discrete Semiconductors Integrated Circuits

3. Early Computers 1951-1958 Vacuum tube memory Input / Output Punch cards Magnetic Tape

4. Electronic Computer Technology Warm-up hot Ran hot tube filaments required constant heating computers required air conditioning Frequent failures

5. Computersafter Vacuum Tubes 1959-1963 Transistor & magnetic core memory Smaller Less power needed

6. Discrete Semiconductor Components in Computers transistors magnetic memory cores Space requirements large but smaller than vacuum tubes cooler Ran much cooler than vacuum tubes

7. Computers: The Big Jump Integrated Circuits millions of semiconductor components in tiny package lower production costs Extremely small Extremely fast Run very cool Very reliable

8. Categories of Computers Super computers Mainframes Minicomputers Microcomputers

9. 5 th Generation: Supercomputers Large (even today) Expensive Found only in major research sites Applications weather scientific modeling oil exploration other research

10. Mainframe Computers Large $$$ Requires teams of experts Large # of users Applications large corporations government hospitals

11. Microcomputer “PC” Rapidly changing technology Low cost Non-proprietary First common in 1980’s

12. Minicomputers First seen in 1970’s Much less expensive than mainframes Medium-sized Proprietary ($$$) parts operating systems Computer used for CT Appropriate Size price Applications imaging, reconstruction archiving

13. Basics InputProcessingOutput

14. Input Manual keyboard mouse Electronic CT detectors CR Plates Input ProcessingOutput u Other u Voice recognition

15. Analog to Digital Conversion (A to D) Analog (continuously varying) Digital (discretely varying)

16. Analog to Digital Conversion (A to D) Many real world inputs are analog voltages CT detector intensity Analog values must be converted to a # to use in a computer 0.2 0.4 0.6 0.8 Input analog voltage 1234 Digital conversion to computer

17. Processing Central Processing Unit (CPU) Arithmetic Logic Internal Memory Scratchpad Input Processing Output

18. Hard copy printer Soft copy CRT InputProcessing Output u Storage disk tape

19. Hardcopy Devices Do not lose information when power is shut off Printers impact (dot matrix) noisy multi-copy non-impact (quiet) ink jet laser Plotters Microfilm

20. Softcopy Devices Lose all information when power shut off Flat-panel monitors

21. Digital to Analog Conversion (D to A) Computer reconstructs digital image set of numbers Computer displays analog image 125 25311111182222176 199192 85 69133149112 77103118139154125120 145301256223287256225 178322325299353333300

22. Computer System Elements Hardware Software People

23. Hardware Computer Peripherals keyboard printer Hardware Software People

24. Hardware Examples Disk Drive Memory Random Access (RAM) Read only (ROM) Mouse Keyboard Cables Hardware Software People

25. Software Instructions to computer Operating System Applications Hardware Software People

26. Operating System Fundamental instructions to hardware What to do when computer first turned on How to interact with hardware CRT Keyboard Mouse Modem Hardware Software People

27. Operating System Computer “face” presented to users Windows DOS MAC OS Dictates how users interact with computer to run application software Hardware Software People

28. Application Software Computer instructions which perform some desired task Balance checkbook Play a game Calculate (reconstruct) a CT image Hardware Software People

29. Application Software quasi-English Usually a quasi-English language Basic Fortran COBOL C Languages provide tools to software developers to efficiently design application software Forms![FDoSurvey]![FExpsSub].Form![KVEff] = Val(Mid$(MyData, 2, 10)) Forms![FDoSurvey]![FExpsSub].Form![KVAVG] = Val(Mid$(MyData, 12, 10)) Forms![FDoSurvey]![FExpsSub].Form![MRMEAS] = Val(Mid$(MyData, 22, 10)) Forms![FDoSurvey]![FExpsSub].Form![TIMEMEAS] = Val(Mid$(MyData, 32, 10)) DumText = Mid$(MyData, 42, 3) 'MsgBox$ (DumText) If Right$(DumText, 1) = "+" Then DumText = Left$(DumText, 2) Else DumText = Left$(DumText, 1) End If 'MsgBox (DumText) MyData = Right$(MyData, Len(MyData) - Len(DumText) - 41) 'MsgBox (MyData) NKvs = Val(DumText) 'MsgBox (NKvs) KVMAX = 0 If NKvs > 0 Then For DumNum = 1 To NKvs 'MsgBox (Val(Mid$(MyData, 10 * (DumNum - 1) + 1, 10))) If (Val(Mid$(MyData, 10 * (DumNum - 1) + 1, 10))) > KVMAX Then KVMAX = (Val(Mid$(MyData, 10 * (DumNum - 1) + 1, 10))) End If Next Forms![FDoSurvey]![FExpsSub].Form![KVMAX] = KVMAX End If DoCmd.Close acForm, "FNeroExp" End Sub

30. People Designers hardware software Users run applications provide input use output

31. Meaningless Slide

32. Storage Hardware Random vs. Sequential Direct (random) access any data can be accessed at any time disks Sequential access data only accessed in serial fashion must pass through unwanted data to reach target data tapes information encoded magnetically

33. Data Storage Technologies (constantly changing) Disks Formats Hard removable non-removable Floppy CD CD-RW CD-R Tape lots of data serial access u Technologies »Magnetic (disks & tape) u re-writable »optical (disks & CD’s) u re-writable u write once

34. Data Communication Features speed cost topology wiring scheme u Data transmission between computers

35. Data Communication Technologies Telephone lines twisted pair wires Coaxial cable Fiber optic cable Microwaves Satellites Radio waves

36. Networks LAN (Local area network) computers connected in one area LAN’s can be connected together WAN (Wide area network) computers connected together over large distances Communications protocols Ethernet uses bus technology Internet

37. File Server Special computer which handles functions for connected computers disk access printing Incorporates security may limit user to selected files or directories may limit # of connections per user may limit times when network available

38. Typical Lan Network Gateway Other Networks

39. Radiology Computer Systems RIS Professional Billing CR CT MRI Digital Dictation Mammography Digital Spot Film Voice to Text Dictation Web Server Insurance Carrier Hospital Admission/Discharge Billing Reports PACS Angio / Digital Subtraction

40. The Computerization of Radiology RISPACS CTCRMRI Digital Fluoro Digital Angio DictationAdmin Radiologist Workstation Radiologist Workstation Radiologist Workstation 3D Workstation Nuc Med Laser Printer Web Browser

41. The Internet Network connecting all computers Originally developed for security Single bomb can’t destroy all U.S. computing facilities Can connect large number of computers in many locations Communicates in finite “packets” Each packet has specific destination (address) Packets can be E-mail Web site linking Allows linking of information