1. Secondary Storage
Backups & Crashes

2. Intro Bits & Bytes Types Magnetic Optical Paper Read & Write
Rapid degradation
Optical
Read…maybe write
Slow degradation
Paper

3. Bits & Bytes 1 Bit – 0 or 1 8-bits – 1 character – 1 Byte
Kilobyte – 1000 bytes
TRS-80 – 4K RAM (1977)
Megabyte – 1,000,000 bytes
30 phonebook pages
1987 Desktop
Gigabyte – 1,000,000,000
One movie
1997 Desktop
Terabyte – 1,000,000,000,000
5,500 copies of every phonebook in the world
2013 Desktop
Petabyte, etc
Not in use other than stacked TB storage

4. Magnetic
HDD
PATA (IDE)
SATA
SCSI
SSD
Hybrid

5. Magnetic

6. Magnetic
FDD 8”
5.25”
3.5”

7. Optical CD
WORM
R/W
DVD
Blu-Ray

8. Cost

9. History 1928 – Mag Tape 1956 – Hard Disk 1966 – DRAM
1970 – Bubble Memory
1976 – 5.25 FDD
1981 – 3.5 FDD
1984 – CD ROM

10. History 1994 – Flash Memory 1995 – DVD 1995 – CD-RW 1999 – Microdrive
2003 – Blu-Ray
2004 – Cloud
2009 – SSD
2010 – Hybrid
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