Upload
lynette-pope
View
256
Download
3
Tags:
Embed Size (px)
Citation preview
Storage
MemoryMemory
• RAM• Virtual Memory• Cache Memory• ROM• Motherboard
Memory:Memory: CPU’s Electronic ScratchpadCPU’s Electronic Scratchpad
Inside the System Unit
A
Module
• Memory Capacitieskilobyte (K or KB), megabyte (M or MB), gigabyte (G or GB)
• Random-Access Memory (RAM)store programs & data being usedeach memory location has an addressvolatilemore is better
Random Access Random Access MemoryMemory
Inside the System Unit
A
Module
In RAM, each memory location has an address, just like a post office box.
data
SIMMs
• you can increase your personal computer’s 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 computer’s main circuit board (cheaper and more efficient than single chips)
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
Cache Memory
• a specialize chip used with the computer’s 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)
MemoryMemoryInside the System Unit
A
Module
• Read-Only Memory (ROM)non-volatileROM BIOS, flash BIOS
• CMOSused to store startup configuration optionseach memory location has an addressvolatile
Motherboard
• large circuit board which contains the microprocessor
• can hold expansion cards
• ports - parallel (printers) and serial (modems)
Plug and Play Plug and Play Inside the System Unit
A
Module
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.
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
• Storage Concepts: The Basics
• Disks and Disk Drives: Putting a Spin on it
• Magnetic Tape: Still Useful
• Optical Storage Media: Seeing the Light
Data Storage
B
Module
Storage Concepts:Storage Concepts:The BasicsThe Basics
Data Storage
B
Module
Device Access speed Cost per MB
MEMORY Cache memory Fastest Highest
RAM memory Fast High
STORAGE Hard disk Medium Medium
CD-ROM disc Slow Low
Backup tape Very slow Lowest
Memory versus Storage
Disks & Disk Drives:Disks & Disk Drives:Putting a Spin on itPutting a Spin on it
Data Storage
B
Module
Before a disk can be used for
storage, it must be formatted
sectors
cluster tracks
Floppy DisksFloppy DisksData Storage
B
Module
A 3 1/2 inch disk
plastic casing
read/write openingsliding metal
shutter
write protection tab
linerdisk
spindle holesector hole
• How Hard Disks Work
• Storage Capacities
• Physical Performance
• Disk Caches
• Hard Disk Interfaces
• Hard Disk Maintenance
• Backup Procedures
• Removable Hard Disks
Hard Disks
B
Module
Data Storage
Magnetic Disks
• both electrical and mechanical
• FAT (File Allocation Table)
• speed
• storage capacity
Disk Drives
• interface to connect to motherboard
• IDE (Integrated Drive Electronics)
• SCSI (Small Computer System Interface)
Hard Disk InterfacesHard Disk InterfacesData Storage
B
Module
Interface type Maximum possible data transferrate (Mbps)
Original IDE 2.1
Standard SCSI 5.0
EIDE (ATA-2) 16.6
Ultra SCSI 20.0
Ultra ATA (Ultra DMA) 33.3
Ultra Wide SCSI 40.0
Removable Hard DiskRemovable Hard DiskData Storage
B
Module
Many new computers come equipped with a Zip drive, a removable hard disk that uses 100MB cartridges. The cartridges cost about $10 each.
Magnetic Tape:Magnetic Tape:Still UsefulStill Useful
Data Storage
B
Module
Quarter-inch cartridge (QIC) tape drives work with cartridges that can hold more than 10MB of
data
Optical Storage Media:Optical Storage Media:Seeing the LightSeeing the Light
Data Storage
B
Module
CD-ROM disks are prerecorded and cannot be altered. CD-ROM provides an excellent way to distribute large amounts of data at little cost.
• CD-ROM
• CD-R
• CD-RW
Optical Storage Media:Optical Storage Media:Seeing the LightSeeing the Light
Data Storage
B
Module
DVD-ROM drives are expected to replace CD-ROM drives as the standard personal
computer equipment in the near future
• DVD
• DVD-ROM
• DVD-RAM
Questions