Digital Electronics and File Management

1. Digital Electronics and File Management Unit D

2. Objectives • Introduce Digital Data Representation • Introduce Integrated Circuits • Explore Microprocessor Performance Factors • Understand Computer Memory: RAM • Explore Computer Memory

3. Objectives • Introduce Computer File Basics • Understand File Locations • Explore File Management • Understand Logical File Storage • Use Files • Understand Physical File Storage

4. Digital Data Representation • The form in which information is conceived, manipulated and recorded on a digital device. • Uses discrete digits/electronic signals • 1,0 (bits - binary digits) • On/Off • Yes/No • Byte = 8 bits = 1 character

5. Coding Systems • Depends on computer • ASCII(7 bits) • Extended ASCII (8 bits - current PCs) • EBCIDIC (8 bits - older IBM machines ) • Unicode (16 bits - good for languages - future)

6. Quantifying Bytes and Bits • Bit = b • Nibble = Half of a byte • Byte = B • Kilobyte (KB) (1024 bytes) • Megabyte (MB) (Million bytes) • Gigabyte (GB) (Billion bytes) • Terabyte (TB) (Trillion bytes)

7. Integrated Circuits A super thin slice of semi–conducting material packed with microscopic circuit elements such as wires, transistors, capacitors, logic gates, and resistors. Bits are represented as electrical pulses that travel over these circuits. Also called a chip, microchip and computer chip.

8. Chip Package Integrated Circuit Uses • Microprocessors • Memory • Support circuitry

9. Microprocessor Packages • DIPs (dual in-line packages) • DIMMs (dual in-line memory modules) • PGAs (Pin-grid arrays) • SECs (single-edge contact cartridges)

10. Microprocessor (Processor) • Designed to process instructions • Largest chip on motherboard • Intel: world’s largest chipmaker (Pentiums) • AMD: Cheaper chips (Athlons)

11. Motherboard • Main circuit board

12. Microprocessor Components

13. Microprocessor Performance • Speed: microprocessor clock set clock speed (MHz or GHz ) • World Size: number of bits the microprocessor can manipulate at one time (32-bit or 64-bit) • Cache: high speed memory (kilobytes)

14. Microprocessor Performance • Instruction Set Type: • CISC (Complete instruction set computer) • RISC (Reduced instruction set computer) • Processing Technique: • Serial • Pipelining • Parallel • Look at benchmark testing to compare

15. Memory Types • Random Access Memory (RAM) • Virtual Memory • Read-Only Memory (ROM) • CMOS

16. RAM Random Access Memory • Temporary (volatile) holding area for data, application software and operating system • Expensive chip set • Circuitry • Less storage than disk • Capacitors hold bits • Capacity measured in MB (64 - 512 MB) • Speed in nanoseconds

17. RAM Types • SDRAM • Synchronous Dynamic RAM • fast and cheap • DIMMS • RDRAM • Rambus Dynamic RAM • faster and more expensive • RIMMs AND SO-RIMMs

18. Virtual Memory • Disk based • Stores parts of programs and data until they are needed by the processor • Works with RAM, but is slower

19. ROM Read-Only Memory • Permanent on a chip from manufacturer • Holds computer start up routine, which are hard-wired instructions • PROM: programmable via “burning” • EPROM: erasable • ROM BIOS (basic input/output system)

20. CMOS Complementary Metal Oxide Semiconductor • Battery powered • More permanent than RAM; less permanent than ROM • Stores basic computer configuration • Must be updated via CMOS setup program when configuration changed

21. Computer File Characteristics • A collection of data on a storage medium • Filename conventions • Filename extension .txt .jpg .exe .doc

22. C:\Music\Reggae\Marley One Love.mp3 Drive letter Primary folder Secondary folder Filename Filename extension File Locations • Device drive letters A: C: D: • Directory • Root Directory (C:\) • Subdirectory or folder (C:\Documents) • File specification or Path • File size and date

23. Deleting Files • Move to Recycle Bin in Windows • Undelete • Empty Bin

24. File Management • Helps you organize your computer files • File/Save and File/Open • Utilities like Windows Explorer or MAC Finder • list, find, move, copy, delete, rename • Save vs. Save As

25. Logical File Storage • Filing cabinet model • Metaphor to help you visualize files on a storage device • Windows Explorer • Folder hierarchy

26. Using Files • Start application (open Word) • Create file (type text) • Save file (File/Save) • Close file and application (File/Exit) • Open file again for editing (File/Open) • Edit file • Save file • File/Save • File/Save As

27. Physical File Storage • Storage medium formatted into tracks /sectors electronically • File system keeps track of names and file locations. • Windows uses FAT32 OR NTFS • Clusters: a group of sectors that speeds up storage and retrieval

28. Physical File Storage • FAT (File Allocation Table) on each disk keeps track of where all files are and which clusters are empty. If damaged, you lose everything. • Defragmentation Utility rearranges files to be stored in contiguous clusters.

29. Tech talk: How a microprocessor executes instructions • Complex task broken down into a series of simple steps or instructions • Instructions are in machine code (0s and 1s) and consist of: • Op code: Operation code like Add, Compare, etc • Operand: data address for operation

30. Tech talk: How a microprocessor executes instructions • Instruction Set is built into processor • Instructional Cycle is the execution of a single instruction Interpret Instruction Fetch Instruction Execute Instruction Increment Instruction Pointer

31. Issue Who invented the computer?

32. Digital Electronics and File Management End