1. An Abacus

2. Babbage’s Difference Engine

3. Electronic Computers  1939–1944, Howard H. Aiken developed the Harvard Mark I—also known as the IBM ASCC.  Grace Hopper worked at Harvard on the Mark I, II, and III, and discovered the first computer bug.  Konrad Zuse worked secretly on his Z3 computer in Germany.

4. Vacuum Tubes

5. Programming ENIAC (U.S. Army photo)

6. Transistors

7. Integrated Circuit Integrated circuit

8. An Early PC

9. External System Components

10. Internal System Components System board Power connectors Adapter card Power supply Slots Drives

11. A System Board Expansion slots RAM CPU AGP slot Ports Drive interfaces

12. A Selection of CPUs

13. A Typical Memory Module

14. Interfaces Internal Interfaces External Interfaces

15. An Example of an Adapter Card Expands computer capabilities by enabling computer to connect to another computer over phone lines Circuit to connect to phone line PCI bus Phone line connection

16. A Hard Disk

17. A Floppy Disk and Drive Front view of a floppy disk drive Floppy disk

18. A CD-ROM Disc and Drive A CD-R disc An internal CD-ROM drive

19. Software  Software is the program code stored on a hardware disk.  Software is written in computer languages like Visual BASIC, C++, Cobol, assembler, and machine language.  Software can be divided into two categories—System software and Application software.

20. System Software

21. Application Software

22. Device Drivers Driver allows OS and device to communicate

23. Firmware Firmware is software stored in memory chips that retains data whether or not power to the computer is on.

24. Counting Marbles in the Decimal System How many? Pail holds 1,000 Can holds 100Cup holds 10

25. Counting Marbles in the Binary System How many? 256 128 64 32 16 8 4 2

26. Counting Marbles in the Hexadecimal System How many?Pail holds 256Can holds 16

27. Computer Values  Bit – A single binary digit  Byte – 8 bits  Nibble – 4 bits  Kilobyte (KB) – 1,000 bytes  Megabyte (MB) – 1,000,000 bytes