CIS 1 - 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 randomly 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 (RAM), 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

Usually refers to the computer’s primary memory

Usually volatile (contents are randomized when computer is powered down)

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, clock ticks per instruction, Bus width, and Word size 

ALWAYS ‑ only one instruction can be processed at a time per CPU core!

 

Relative Speed Rank 

 

Hard Disk, 

CDs and DVDs

Diskette 

Tape Drive

 

Disk Drive 

 

Disks (hard or floppy) are mounted on this

 

Tape Drive 

 

Magnetic tapes are mounted on this

 

Coprocessor 

 

Special purpose microprocessor that relieves the CPU to increase speed 

Math Coprocessor (Math or Floating Point accelerator) 

Graphics Coprocessor (Graphics accelerator) 

Graphics accelerator cards are usually equipped with their own RAM

 

Intel CPUs 

 

8080, 8088, 80286 (i286), 80386 (i386), 80486 (i486), Pentium, Pentium Pro, Pentium II, III, and IV, Core 2, Core i5, Core i7, Xeon, Itanium

Optical Storage Media

Digital Video Discs (DVDs)

Compact Discs (CDs)

Written and read using a laser

Laser reflects off a land indicating a logical one

Laser is scattered by a pit indicating a logical zero

+R and –R indicate write-once media

+RW and –RW indicate read/write media

Smart Card

Looks like a magnetic strip credit card

Contains a processor and has input, process, output, and storage capabilities.

Cache Memory

May be on the CPU chip or external to the CPU
Very fast
More expensive than RAM
Used to store frequently used commands or data to accelerate performance

 

Ports

Serial

Parallel

USB

MIDI

1394 (Firewire)

 

RAID Array

Redundant Array of Independent Disks

Multiple associated disks

Mirroring provides redundancy for backup

Striping provides speed

Level 5 combines redundancy and striping

Disk Partitions

Separates a 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)