Transcript Computer Concepts 97-123

Digital Electronics
and File Management
Unit D
Objectives
Introduce Digital Data
Representation
Introduce Integrated Circuits
Explore Microprocessor
Performance Factors
Understand Computer Memory:
RAM
Explore Computer Memory
Objectives
Introduce Computer File Basics
Understand File Locations
Explore File Management
Understand Logical File Storage
Use Files
Understand Physical File Storage
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
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)
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)
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.
Integrated Circuit Uses
Microprocessors
Memory
Support circuitry
Chip
Package
Microprocessor Packages
DIPs (dual in-line packages)
DIMMs (dual in-line memory
modules)
PGAs (Pin-grid arrays)
SECs (single-edge contact
cartridges)
Microprocessor (Processor)
Designed to process
instructions
Largest chip on
motherboard
Intel: world’s largest
chipmaker (Pentiums)
AMD: Cheaper chips
(Athlons)
Motherboard
Main circuit board
Microprocessor Components
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)
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
Memory Types
Random Access Memory
(RAM)
Virtual Memory
Read-Only Memory (ROM)
CMOS
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
RAM Types
SDRAM
– Synchronous Dynamic RAM
– fast and cheap
– DIMMS
RDRAM
– Rambus Dynamic RAM
– faster and more expensive
– RIMMs AND SO-RIMMs
Virtual Memory
Disk based
Stores parts of programs and
data until they are needed by the
processor
Works with RAM, but is slower
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)
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
Computer File Characteristics
A collection of data on a storage
medium
Filename conventions
Filename extension
.txt
.jpg
.exe
.doc
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
C:\Music\Reggae\Marley One Love.mp3
Drive
letter
Primary
folder
Secondary
folder
Filename
Filename
extension
Deleting Files
Move to Recycle Bin in Windows
Undelete
Empty Bin
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
Logical File Storage
Filing cabinet model
Metaphor to help you
visualize files on a
storage device
Windows Explorer
Folder hierarchy
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
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
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.
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
Tech talk: How a microprocessor
executes instructions
Instruction Set is built into
processor
Instructional Cycle is the execution
of a single instruction
Fetch Instruction
Interpret Instruction
Execute Instruction
Increment Instruction Pointer
Issue
Who
invented
the
computer?
Digital Electronics
and File Management
End