This document discusses different types of computer memory and storage systems. It describes the hierarchy of internal memory, including CPU memory, cache memory, and primary/main memory. It explains different types of random access memory like SRAM, DRAM, and read only memory like ROM, PROM, EPROM, and flash memory. External storage systems covered include magnetic tapes and disks, optical disks like CDs and DVDs, solid state drives, and removable storage devices like floppy disks and flash drives. The document provides details on the components, workings, and storage capacities of these different computer memory and storage technologies.
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1. COMPUTER APPLICATION
IN MANAGEMENT
UNIT 2 ¨C COMPUTER
SYSTEM
Submitted by:-
Kh. Santosh Singh
Under the guidance of:-
Dr. S. Somokanta
2. Recap¡.
? Characteristics of Computer
? Generation of Computers
? Era of Personal Computers
? Digital Computers
? Micro Computers
13. CPU Memory
? Internal Processor Memory
? Embedded into the processor
? High Speed Register
? Actual Processing
14. Main Memory
? Primary Memory
? Communicates directly with the CPU
? 2 types - RAM & ROM
? RAM ¨C Random Access Memory
? ROM ¨C Read Only Memory
15. Random Access Memory
? Read-Write-Memory
? Random access of data
? Volatile in nature
? Manufactured with Bipolar or MOS technology
? Types ¨C SRAM, DRAM, SDRAM, RDRAM,
DDR SDRAM, FPM DRAM & EDO DRAM
* MOS ¨C Metal Oxide Semiconductor
16. RAM Types
? SRAM- Static RAM
? DRAM- Dynamic RAM
? SDRAM- Synchronous Dynamic RAM
? RDRAM- Rambus Dynamic RAM
? DDR SDRAM- Double Data Rate SDRAM
? FPM DRAM- Fast Page Mode DRAM
? EDO DRAM- Extended Data Out DRAM
17. Read Only Memory
? Non Volatile in nature
? Data / Program not modifiable
? Store BIOS program
? Types ¨C
? Masked ROM ¨C Non user programmable
? PROM, EPROM, EEPROM, Flash Memory ¨C User
programmable
18. PROM, EPROM, EEPROM
? Programmable ROM
? Erasable Programmable ROM
? Electrically Erasable Programmable ROM
? Flash Memory ¨C
Type of EEPROM that uses in-circuit-wiring
Much faster than traditional EEPROM
19. Cache Memory
? Small & Fast but Expensive
? Placed between CPU and Main memory
? Size ranges from 64KB to 2MB
? Types:
? Primary or Level 1 Cache (on-chip cache)
? Secondary or Level 2 Cache (on-board cache)
? Level 3 Cache (on-board cache)
20. External Memory
? Auxiliary Memory / Secondary Storage
? Store larger amount of data / information
? Non Volatile in nature
? Categories:
? Sequential Access Devices
? Direct Access or Random Access Devices
21. Magnetic Tape
? Sequentially accessed
? Read / Write with HEAD device
? 2 popular forms:
Detachable Reel Magnetic Tapes and
Tape Cartridges
? Storage Capacity of a tape = Data Recording Density X
Length of the Tape
22. Magnetic Disks
Track
? Circular plate of metal/plastic Sector
? Coated with magnetized material
? Direct Access Storage
? Rewritable
? Mapping or Formatting
? Low-level formatting
? High-level formatting
23. Disk Drive
? A generic term
? A device on which disk is mounted
? Consists of motor, arms assembly with heads
? Speed ranging from 3600 ¨C 7200 RPM
? Information recorded during disk rotation
? Uses : Floppy disk drive
Hard disk drive
24. Floppy Disk
? Removable storage device
? Out of market
? Size ranges from 100 KB ¨C 200 MB
? 3 ? inch HIFD
1998-99
25. Hard Disk
? Invented in the
1950¡¯s
? Originally called
¡®Fixed Disk¡¯ or
¡®Winchesters¡¯
? Storage Capacity =
Number of recording surfaces X
Number of tracks per surface X
Number of sectors per track X
Number of bytes per sector
? Internal ? External ? Solid-state-drive(SSD)
26. RAID
? Redundant Array of Inexpensive Disks
? Higher storage capacity
? Uses mainly in the Mainframes and Servers
27. Optical Disk
? Made of plastic plate
with light sensitive
recording surface
? Capable of storing vast
amount of data
? Single spiral track
? Sectors are of same
length
? Use laser beams for
Read / Write
? E.g. CD-ROM, WORM
Disc, Erasable Optical
Disc, DVD-ROM, Blue
Ray Disc
Storage capacity = No. of Sectors X No. of Bytes per Sector
28. Flash Drive
? Also known as ¡®Thumb Drive¡¯ or ¡®Pen Drive¡¯
? Not actually a drive ¨C no moving parts
? Based on EEPROM technology
? Essential components
1. Standard A USB Plug
2. USB Mass Storage Controller
3. Flash Memory Chip