Police Technology Chapter Two

1. Police Technology Chapter Two Computer Basics Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

2. Learning Objectives • Understand the basic hardware and software components of a Desk Top Personal Computer (PC). • The difference between Operating Systemsand Applications software. • The difference between and Flat File and Relational Database Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

3. Binary Number System A mathematical counting scheme that has only two digits – zero (0) and one (1) which are combined to represent our ten- digit counting scheme. Today’s computers use this off/on scheme to represent the binary digits, commonly referred to as bits, 1 and 0. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

4. Binary Number System It is simple for computers to translate binary digits into a sixteen digit-based code called hexadecimal. This coding system is a compromise between our abilities and the computer that allows us to interface. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

5. ASCII The standard computer code configuration that works with computer bits is called the American Standard Code for Information Interchange (ASCII). Binary digits A byte is eight bits, or a series of eight ones and zeros. Byte ASCII Words you can read! Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

6. Interface Means to Interact • User interface is how we interact with the computer, e.g. the keyboard and mouse are user interface inputs and the monitor is the computer’s user interface output Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

7. Your Computer as a System A computer system can considered as three broad categories of components: • Hardware • Software • Firmware Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

8. Your Computer as a System The user is a human being. The input devices are the computer keyboard, mouse, andmicrophone. The output devices are the monitor, speakers, printer, and various storage media. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

9. Hardware Input/output devices are referred to as peripheral devices. Think of a peripheral device as any device not inside the computer case. They communicate with the main part of the computer using ports. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

10. Hardware In addition to receiving information directly from human users via input devices, computers can receive information from other computers. This is done via a network, e.g. the Internet. Network information can come to the computers through: • Hard lines(standard telephone line) • Wireless (via radio signals) Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

11. Hardware Computers have the ability to store information: • Floppy Disks • Compact Discs (CDs) • Digital Video Discs (DVDs) Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

12. Inside your Computer The systems board, or motherboard, is the brain of the computer. The motherboard contains a series of micro chips that are connected together by circuitry. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

13. Inside your Computer Circuits, like wires or cables, transmit electrical signals containing binary data between the various microchips. The microchips in the computer can detect the presence or absence of electronic impulses. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

14. Inside The Computer The Motherboard contains three types of memory chips: • The Central Processing Unit (CPU) • The Read-only Memory (ROM) • The Random Access Memory (RAM) Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

15. Inside your Computer The CPU has three core sets of instructions that it carries out: • Mathematical computations (addition, subtraction, division); • Moving data or information from one memory location to another; and, • Making decisions and moving to a different set of instructions based upon those decisions. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

16. Inside your Computer Random Access Memory (RAM) chips contain information only when your computer is on. When you turn off the computer, the memory in the RAM disappears. Also known as Volatile storage! Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

17. Inside your Computer • Read Only Memory (ROM) Contains the basic set of instructions that are required to start the computer. • Memory was installed during the manufacturing process. • ROM (BIOS instructions) is a permanent part of the chip. Also known as Non- Volatile storage! Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

18. Inside your Computer • The Motherboard contains….. • A Complementary Metal Oxide Semi-conductor (CMOS)configuration chip. • A system clock. • Expansions slots. • RAM memory. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

19. Inside your Computer • The CMOS Chip: • Responsible for remembering what hardware is in your computer. • Necessary for your computer to initially organize itself. If you added a new drive, card, or peripheral device, your CMOS information would change. • Volatile (information can be lost) so it has its own battery with constant power Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

20. Inside your Computer • Random Access Memory (RAM) …………. • Contains information your computer is working with now (What is on the screen). • Has to be limited in the amount of information it can contain. • Once you are finished using the RAM and move on to another project, what was in RAM is dumped. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

21. Inside your Computer Cache Memory contains memory your computer anticipates you might need, similar to the human brain. It makes assumptions about what information you might need based on certain programming. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

22. Inside your Computer • A BUS Contains the electrical pathways and directions for use of those pathways that the information uses while inside a computer. • The small metal tracings in the circuit board take the place of wires to conduct electricity. • The bus is these traces and the instructions for their use. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

23. Inside your Computer CMOS Chips Continually hold the information on the configuration of your computer. When you turn on the computer, the startup process is called a booting. When a computer is booted from the power- off condition, it is called a “hard boot.” If you push the reset button, you are performing a “soft boot.” Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

24. Inside your Computer The Random Access Memory (ROM) contains a set of permanent instructions known as the basic input/output system (BIOS). Sometimes referred to as the ROM BIOS or Flash BIOS. ROM chips are a hybrid of both hardware and software. It is a physical component with embedded software. ROM chips are sometimes referred to as firmware. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

25. Information on the Motherboard, except the ROM chip, is volatile. Inside Your Computer Long term or secondary storage are non-volatile: • Hard disks; • Zip disks; • Floppy disks; Cassette tapes; • CD-ROMs; and, • DVDs. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

26. Instructions that tell hardware what to do; or, A set of instructions written in a language that the computer can understand. Two broad classifications of software: Operating Systems (also called platform) Applications Software Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

27. Operating Systems The operating system is the computer’s traffic cop. • Tells the computer what to do. • The computer software that controls and coordinates the interaction among the hardware elements and between the hardware and the application programs. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

28. Operating Systems After your computer has booted and CMOS hands your computer over to the operating system the operating system has two primary functions: • Managing the hardware and software. • It provides application program interface (API). Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

29. Disc Operating System DOS is probably the most common operating system. Users interface with a DOS in one of three ways: • A command driven interface; • A menu-driven interface; or, • An icon-driven interface. Most police employees work with an icon-driven interface that is also called a graphical user interface (GUI). Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

30. Applications Applications software allows the user to work with information in the computer. Applications are specific programs that allow the user to do specific tasks such as word processing. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

31. Databases A collection of organized information that is centrally located and designed to meet the needs of users. There are two classifications of databases: • Flat file • Relational Database Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

32. Forced Choice Formats Many state and local police agencies use software that allows them to configure data entries to match their specific data dictionary. Through the use of forced-choice formats, GUI software restricts data entries to previously determined attributes, properties or characteristics. Screen capture provided by Crimestar Corporation Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

33. Useful Terms • Multi-media is the different forms of media being used by any particular application. • Multimedia applications can include graphics, animation, sound, and video elements • A scalable system can be adapted and expanded to meet increased needs. • Most legacy systems are proprietary. • The system manufacturer (either hardware, software, or both) will not reveal the systems specifications so that other firms may not duplicate the product. • Also known as a closed architecture. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster

34. Police Technology Discuss criminal justice issues www.criminaljustice-online.com Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster