CS3 - Kurtz  Santa Monica College 

THE CPU AND STORAGE

 

CPU  Sometimes referred to as the brain of the computer.
Volatility  The ability of a storage device to preserve and store data.
Bit  A digit with either of two values, 1 or 0.
Byte String of bits used to represent a letter, number, or punctuation mark. 8 bits.
Kilobyte  1,000 bytes (KB, Kbyte)
Megabyte  1,000 KB (MB, Mbyte)
Gigabyte  1,000MB (GB, Gbyte)
ASCII  The text encoding system used primarily with micro and minicomputers.
Sequential storage  things are recorded one after the other.
Random Access storage  data is recorded wherever there is space available.
Bus  The electronic connections between the CPU, storage, and other peripherals inside the computer
Floppy Disks A major advantage of floppy disks is their low cost 
Can be damaged by dust, heat, fingerprints
Motherboard  The board that contains the CPU, primary memory, and expansion slots.
Upgrade Adding expansion cards to the computer 
Replace CPU or mother board with newer model 
Adding additional output devices 
Boost speed and amount of memory
RAM Random Access Memory 
Read & Write 
Essential to rapid access of information 
Different from the hard drive
ROM  Read Only Memory 
Can be read but not written by the user
Magnetic Tape Used to back up and archive data
Disk access time  Time to begin reading data
Slow Microprocessors: Boot slowly 
Process commands slowly 
May not run newer software
CPU speed factors  Clock speed and clock ticks per instruction 
Bus width 
Word size 
ALWAYS - only one instruction can be processed at a time!
Relative Speed Rank  RAM
Hard Disk 
CDs and DVSc 
Tape Drive
Disk Drive  Disks (hard or floppy) are mounted on this
Tape Drive  Mag tapes are mounted on this
Coprocessor  Special purpose microprocessor that relieves the CPU to increase speed 
Video Coprocessor (Graphics accelerator) 
Video accelerator card usually equipped with own RAM
CPUs  8080 
8088 
80286 (286) 
386 
486
Pentium 
i3, i5, i7
BIOS Basic Input/Output System
Contains instructions that are executed at start-up (bootstrap start)
Executes the Power On Self-Test (POST)
Launches Operating System
Searches multiple drives for Operating System (OS) in a pre-defined sequence
Issues an error message if OS is not found only after searching all drives indicated in sequence
Ports Serial (COM1 - COM4)
Parallel (LPT1, LPT2)
USB
MIDI
1394 (Firewire)
IrDA
FIR
RAID Array Redundant Array of Independent Disks
Multiple associated disks
Mirroring provides redundancy for backup
Striping provides speed
RAID 0 - Striping only
RAID 1 - Mirroring (for data redundancy)
RAID 5 - Combination of data redundancy and data striping
Disk Partitions Separates hard drive into "logical" drives
Used to support multiple operating systems
Disk Controllers IDE (Integrated Drive Electronics)
EIDE (Extended IDE)
SCSI (Small Computer Systems Interface)
Reading The process of accessing data, instructions, and information that has already been stored on a storage device.
Writing The process of storing data, instructions, and information onto a storage device.
CD Compact Disk
Type of Optical Disk
0s and 1s are represented by pits and lands
Pits are written by a high powered laser
CDs are read by a low powered laser
CD-R Compact Disk-Read
Write Once, then Read-only
CD-RW Compact Disk-ReWritable
Can be written to, then written over, indefinitely
DVD-ROM Digital Video Disk, Digital Versatile Disk
Read Only Memory
Written by manufacturer, read-only to consumers
Optical disk similar to CDs, but far more dense
DVD+RW Type of rewritable DVD
Smart Card Similar to a credit card or debit card, but with internal circuitry
Typically contains a processor
Typically has input, output, and storage capabilities