1. Digital Electronics and File Management
Unit D

2. Objectives Introduce Digital Data Representation
Introduce Integrated Circuits
Explore Processor 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
Byte = 8 bits = 1 character

5. Numeric Data
Consists of numbers representing quantities used in arithmetic operations.
Binary system, “Base 2”
1,0 (bits - binary digits)
On/Off, Yes/No

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

7. 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)

8. Also called a chip, microchip and computer chip.
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.
Info web: integrated circuits
Also called a chip, microchip and computer chip.

9. Integrated Circuits (cont.)
Chips are classified by number of components they contain
SSI (small-scale integration), less than 100 components per chip
ULSI (Ultra large-scale) over 1 million
Semi conducting materials used to make chips
Silicon and germanium

10. Integrated Circuit Uses
processors
Memory
Support circuitry
Chip
Package
Info web: processor update

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

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

13. Motherboard
Main circuit board

14. Inside the System Unit
The system unit of a PC is the case that houses processing hardware and other hardware.
All of the hardware contained within the system unit is connected to the system board or motherboard.

16. CPU
The CPU (central processing unit) does the vast majority of processing for a computer.
CPUs contains a variety of circuitry and components and are connected to the motherboard.
Also called the processor or microprocessor.

17. CPU, Cont’d.
Processing speed (clock speed) is measured in megahertz (MHz) or gigahertz (GHz) and measures the number of clock ticks per second.
A computer word is a group of bits or bytes that a CPU can manipulate at one time.
Other factors that affect the speed of the computer include the amount of RAM and cache memory, bus width, and bus speed.

18. Memory: RAM
RAM (random access memory) is the computer’s main memory and is used to temporarily storage programs and data with which it is working.
RAM is volatile (erased when the power to the PC goes off).
RAM comes in a variety of types, speeds, and size. Types of RAM include:
DRAM
SRAM
SDRAM
DDR SDRAM
RDRAM
DDR-II SDRAM

19. Memory: Other Types
Cache memory—fast memory chips located on or close to the CPU chip (L1, L2, and L3).
Registers—high speed memory built into the CPU.
ROM (read-only memory)—non-volatile chips inside which data or programs are stored.
Flash memory—non-volatile memory that can be erased and reused. Used both within the PC and for portable storage media (e.g digital cameras).

20. Buses
Buses are electronic paths that data travels around on a computer system.
Internal buses move data around within the CPU.
Expansion buses establish links with peripheral devices.
ISA, PCI, AGP, USB, FireWire.

22. Expansion Slots and Cards
Expansion for desktop PCs.
Expansion cards can be inserted into expansion slots on the motherboard.
Some external devices can be plugged into existing USB or FireWire ports without adding another expansion card.
PC cards—used with notebook PCs.
Expansion for handhelds and mobile devices—can have proprietary, PC card, or SDIO slot.

23. Ports Connectors to which devices can be attached. Common ports:
Serial
Parallel
SCSI
USB
FireWire
Network
Keyboard
Mouse
Monitor
Modem
MIDI
IrDA
Game

25. How the CPU Works
The CPU is a collection of electronic circuits and components.
Impulses from an input device passes through RAM and enters the CPU via a system bus.
Within the CPU the impulses move through the circuits and components to create new impulses.
Eventually, a set of electronic impulses leaves the CPU for an output device.

26. Typical CPU Components
Arithmetic/logic unit (ALU)
Control unit
Registers
Prefetch unit
Decode unit
Internal cache
Bus interface unit

28. The System Clock and the Machine Cycle
The system clock synchronizes the computer’s operations.
The machine cycle is the series of operations involved in the execution of a single, machine-level instruction.
Fetch
Decode
Execute
Store

30. Making Computers Faster Now and in the Future
Speeding up your system today.
Add more memory.
Perform system maintenance.
Buy a larger or second hard drive.
Upgrade your Internet connection.
Upgrade your video card.
Upgrade your CPU.

31. Processor Components

32. Processor Performance
Speed: processor clock set clock speed (MHz or GHz )
Word Size: number of bits the processor can manipulate at one time (32-bit or 64-bit)
Cache: high speed memory (kilobytes)

33. Processor 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
Info web: benchmark
Lab: benchmarking

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

35. 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 ( MB)
Speed in nanoseconds
Makes the most noticeable difference

36. RAM Types SDRAM RDRAM Synchronous Dynamic RAM fast and cheap DIMMS
Most popular
RDRAM
Rambus Dynamic RAM
faster and more expensive
RIMMs AND SO-RIMMs

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

38. ROM Permanent on a chip from manufacturer
Read-Only Memory
Permanent on a chip from manufacturer
Holds computer start up routine, which are hard-wired instructions
Only way to change is to replace ROM chip
ROM BIOS (basic input/output system)

39. CMOS Battery powered More permanent than RAM; less permanent than ROM
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

40. Computer Ads Includes: capacity, speed, and type of RAM
Also maximum RAM that can be installed
Example:
512 MB 400 MHZ SDRAM
CD screen tour: filename extensions
capacity
speed
type

41. Computer File Characteristics
A collection of data on a storage medium
Filename conventions
Filename extension
CD screen tour: filename extensions
.txt
.jpg
.exe
.doc

42. C:\Music\Reggae\Marley One Love.mp3
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
Filename extension
Filename
Secondary folder
Primary folder
Drive letter
C:\Music\Reggae\Marley One Love.mp3

43. Deleting Files
Move to Recycle Bin in Windows
Undelete
Empty Bin

44. 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
CD screen tour: save as dialog box
CD screen tour: operating system file managers

45. Logical File Storage Filing cabinet or tree model
Metaphors to help you visualize files on a storage device
Windows Explorer
Folder hierarchy
Lab: working with Windows Explorer

46. 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 (with changes, or rename)
File/Save
File/Save As

47. Organizing Files On your computer:
Give files and folders descriptive names
Keep file extensions so files open with correct software
Group similar files into folders
Organize folders from top-down to make retrieval and backup easier

48. Physical File Storage
Storage medium formatted into tracks /sectors electronically
File system keeps track of names and file locations.
Windows uses FAT32 OR NTFS
Backup your index file
Clusters: a group of sectors that speeds up storage and retrieval
CD screen tour: formatting a disk

49. 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.

50. Tech talk: How a processor 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

51. Digital Electronics and File Management
End