Storage

1
Storage
2
Memory

• RAM
• Virtual Memory
• Cache Memory
• ROM
• Motherboard

3
Inside the System Unit
Memory CPUs Electronic Scratchpad

• Memory Capacities
• kilobyte (K or KB),
• megabyte (M or MB),
• gigabyte (G or GB)
• Random-Access Memory (RAM)
• store programs data being used
• each memory location has an address
• volatile
• more is better

Module
A
4
Inside the System Unit
Random Access Memory
Module
A
data
In RAM, each memory location has an address, just
like a post office box.
5
SIMMs

• you can increase your personal computers RAM by
  buying extra memory chips to install in your
  memory board or by purchasing a Single IN-Line
  Memory Module, SIMMs, a board that contains
  memory chips
• A SIMM board plugs into the computers main
  circuit board (cheaper and more efficient than
  single chips)

6
Virtual Memory

• enables a computer to execute programs that
  require more memory than is in RAM by dividing it
  into smaller pieces and use part of the hard disk
  as an extension

7
Cache Memory

• a specialize chip used with the computers memory
• faster more expensive than RAM chips
• stores most frequently used data and instructions
• newer PCs have cache (L1 and L2) within the
  microprocessor chip
• Usually L1 is smaller (128K) than L2 (can go up
  to 512K)

8
Inside the System Unit
Memory

• Read-Only Memory (ROM)
• non-volatile
• ROM BIOS, flash BIOS
• CMOS
• used to store startup configuration options
• each memory location has an address
• volatile

Module
A
9
Motherboard

• large circuit board which contains the
  microprocessor
• can hold expansion cards
• ports - parallel (printers) and serial (modems)

10
Inside the System Unit
Plug and Play
Module
A
Microsoft and Intel created the Plug and Play
(PnP) standard. This standard requires special
chips on the motherboard, compatible hardware
that is expressly compatible with the Plug and
Play standard, and a system BIOS that supports
Plug and Play.
11
Speed and Power

• speed is always associated with computers
• power is a derivative of speed plus other factors
• what make a computer go faster, there are several
  factors
• memory size, microprocessor speed, bus line size,
  cache

12
Data Storage

• Storage Concepts The Basics
• Disks and Disk Drives Putting a Spin on it
• Magnetic Tape Still Useful
• Optical Storage Media Seeing the Light

Module
B
13
Storage Concepts The Basics
Data Storage
Module
B
Memory versus Storage
14
Disks Disk Drives Putting a Spin on it
Data Storage
sectors
Before a disk can be used for storage, it must be
formatted
Module
B
cluster
tracks
15
Floppy Disks
Data Storage
write protection tab
liner
plastic casing
disk
Module
sector hole
B
spindle hole
read/write opening
sliding metal shutter
A 3 1/2 inch disk
16
Hard Disks
Data Storage

• How Hard Disks Work
• Storage Capacities
• Physical Performance
• Disk Caches
• Hard Disk Interfaces
• Hard Disk Maintenance
• Backup Procedures
• Removable Hard Disks

Module
B
17
Magnetic Disks

• both electrical and mechanical
• FAT (File Allocation Table)
• speed
• storage capacity

18
Disk Drives

• interface to connect to motherboard
• IDE (Integrated Drive Electronics)
• SCSI (Small Computer System Interface)

19
Hard Disk Interfaces
Data Storage
Module
B
20
Removable Hard Disk
Data Storage
Module
B
Many new computers come equipped with a Zip
drive, a removable hard disk that uses 100MB
cartridges. The cartridges cost about 10 each.
21
Magnetic Tape Still Useful
Data Storage
Quarter-inch cartridge (QIC) tape drives work
with cartridges that can hold more than 10MB of
data
Module
B
22
Optical Storage Media Seeing the Light
Data Storage

• CD-ROM
• CD-R
• CD-RW

Module
B
CD-ROM disks are prerecorded and cannot be
altered. CD-ROM provides an excellent way to
distribute large amounts of data at little cost.
23
Optical Storage Media Seeing the Light
Data Storage

• DVD
• DVD-ROM
• DVD-RAM

Module
B
DVD-ROM drives are expected to replace CD-ROM
drives as the standard personal computer
equipment in the near future
24
Questions