INTRODUCTION
TO TIME TRAVEL

-OR-

1

HOW TO SEND YOUR FILES TO THE FUTURE
TIME TRAVEL:
A MODIFIED DEFINITION

2

COMMUNICATION
ACROSS TIME AND SPACE
3

A BRIEF HISTORY
OF TIME TRAVEL
RECENT ATTEMPTS AT TIME TRAVEL
INFORMATION PRESERVATION
A long time ago…

Today

Analog

The Future!
Today

Digital

5

REQUIRES DIGITAL PRESERVATION
WHAT DOES ‘DIGITAL’
ACTUALLY MEAN?

6

(FOR STORAGE)
MAGNETIC MEDIA: HARD DRIVES

7

Peaks = 1s
Troughs = 0s
8

SOLID STATE MEDIA: SD CARDS
9

OPTICAL MEDIA: CDS
A QUESTION OF
REPRESENTATION

=

“I am the wisest
man alive, for I
know one
thing, and that
is that I know
nothing.”
-Plat...
BIT ROT:
THE DEGRADATION OF BITS
OVER TIME

"I am the wisest
man"alive, fob I know one
thing, and that is that I...
BIT
LOSS
& DIGITAL
PHOTOS

12

Images from Melanie Willhide‟s
“to Adrian Rodreguez with love”
http://www.vonlintel.com/Mel...
ALMOST LOST

BBC Domesday Project 1986

13

NASA images from first Lunar
Orbiter 1966
14

DOMESDAY PROJECT
DIGITAL PRESERVATION
STRATEGIES
Format Choice
Documentation
Migration
Emulation
Hashing/checksums
File Identification

15
...
1. FORMAT CHOICE
Hardware

16

Software
NDIIPP

17

http://www.digitalpreservation.gov/formats/index.shtml
http://www.digitalpreservation.gov/

18

THE LIBRARY OF CONGRESS:
DIGITAL PRESERVATION
2. DOCUMENTATION & METADATA
• File Type
Word Doc
• Software Version
MS Word 2010

File Name
File Size
Number of Words
Tota...
3. MIGRATION

20

• The transfer of
a bit stream
(the 1s and 0s)
from one
medium to
another.
21

FINDING THE HARDWARE
MIGRATION
Similar to
photocopying –
including the
imperfections.

22

Data can be lost or
corrupted in the
transfer.
WRITE BLOCKERS
• Prevents
inadvertently
overwriting digital
information.

23

• Allows „read‟
commands to
pass, blocks „wr...
4. EMULATION
Creates an
environment that
„tricks‟ the software
into functioning as if
it was in its original
computing
env...
EMULATION &
THE GAMING COMMUNITY

"The Old Version Flickers More": Digital Preservation from the User's
Perspective

25

h...
https://archive.org/details/historicalsoftware

26

BROWSER BASED EMULATION
5. HASHING/CHECKSUMS
How they work:
An algorithms „reads‟ a digital object and, based upon the 1s
and 0s that make up that...
HASHING
MD5 Hash

Corrupted File

FD7D5993
062D270F
482E00BD
E64D35FE

461D5E8093
B94401EAF
12E442CEA
B908

28

Original F...
http://download.cnet.com/MD5-SHA-Checksum-Utility/3000-2092_410911445.html

29

HASHING
30

HASHING IN TWO STEPS
IDENTIFYING MYSTERY FILES
.hqx? .mkv? .ape?

31

You have to identify what a file is in order to figure
out what software ...
6. FILE IDENTIFICATION

32

Step 1: Google the file extension
33

IDENTIFYING MYSTERY FILES
IDENTIFYING MYSTERY FILES
Step 1: Google the file extension

34

Step 2: If step 1 fails, use DROID
http://www.nationalarchives.gov.uk/information-management/our-services/dc-file-profiling-tool.htm

35

Digital Record Obje...
IDENTIFYING MYSTERY FILES
Step 1: Google the file extension
Step 2: If step 1 fails, use DROID

36

Step 3: If step 2 fail...
HXD HEX EDITOR

37

http://download.cnet.com/HxD-Hex-Editor/3000-2352_4-10891068.html
38

HEX EDITOR VIEW
FILE SIGNATURES/MAGIC NUMBERS
• Every file type has a digital „finger print‟
near the beginning of its code, sometimes
cal...
WIKIPEDIA’S FILE SIGNATURE LIST

40

http://en.wikipedia.org/wiki/List_of_file_signatures
IF YOU HAVE QUESTIONS
ABOUT DIGITAL PRESERVATION

41

THE LIBRARY IS HERE TO HELP
Questions?

Shea Swauger
Data Management Librarian
Morgan Library, 210E
shea.swauger@gmail.com

42

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Introduction to Time Travel -or- How to Send Your Files to the Future

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Introduction to digital recovery and digital preservation.

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Introduction to Time Travel -or- How to Send Your Files to the Future

  1. 1. INTRODUCTION TO TIME TRAVEL -OR- 1 HOW TO SEND YOUR FILES TO THE FUTURE
  2. 2. TIME TRAVEL: A MODIFIED DEFINITION 2 COMMUNICATION ACROSS TIME AND SPACE
  3. 3. 3 A BRIEF HISTORY OF TIME TRAVEL
  4. 4. RECENT ATTEMPTS AT TIME TRAVEL
  5. 5. INFORMATION PRESERVATION A long time ago… Today Analog The Future! Today Digital 5 REQUIRES DIGITAL PRESERVATION
  6. 6. WHAT DOES ‘DIGITAL’ ACTUALLY MEAN? 6 (FOR STORAGE)
  7. 7. MAGNETIC MEDIA: HARD DRIVES 7 Peaks = 1s Troughs = 0s
  8. 8. 8 SOLID STATE MEDIA: SD CARDS
  9. 9. 9 OPTICAL MEDIA: CDS
  10. 10. A QUESTION OF REPRESENTATION = “I am the wisest man alive, for I know one thing, and that is that I know nothing.” -Plato 10 = 00100010010010010010000001100001011 01101001000000111010001101000011001 01001000000111011101101001011100110 11001010111001101110100001000000110 11010110000101101110001000000110000 10110110001101001011101100110010100 10110000100000011001100110111101110 01000100000010010010010000001101011 01101110011011110111011100100000011 01111011011100110010100100000011101 00011010000110100101101110011001110 01011000010000001100001011011100110 01000010000001110100011010000110000 10111010000100000011010010111001100 10000001110100011010000110000101110 10000100000010010010010000001101011 01101110011011110111011100100000011 01110011011110111010001101000011010 01011011100110011100101110001000100 00011010000101000101101010100000110 1100011000010111010001101111
  11. 11. BIT ROT: THE DEGRADATION OF BITS OVER TIME "I am the wisest man"alive, fob I know one thing, and that is that I onow nothing." -Plato -Plato Original Text 3 Bits Corrupted 11 “I am the wisest man alive, for I know one thing, and that is that I know nothing.”
  12. 12. BIT LOSS & DIGITAL PHOTOS 12 Images from Melanie Willhide‟s “to Adrian Rodreguez with love” http://www.vonlintel.com/MelanieWillhide.html
  13. 13. ALMOST LOST BBC Domesday Project 1986 13 NASA images from first Lunar Orbiter 1966
  14. 14. 14 DOMESDAY PROJECT
  15. 15. DIGITAL PRESERVATION STRATEGIES Format Choice Documentation Migration Emulation Hashing/checksums File Identification 15 1. 2. 3. 4. 5. 6.
  16. 16. 1. FORMAT CHOICE Hardware 16 Software
  17. 17. NDIIPP 17 http://www.digitalpreservation.gov/formats/index.shtml
  18. 18. http://www.digitalpreservation.gov/ 18 THE LIBRARY OF CONGRESS: DIGITAL PRESERVATION
  19. 19. 2. DOCUMENTATION & METADATA • File Type Word Doc • Software Version MS Word 2010 File Name File Size Number of Words Total Editing Time Creation Date Last Modified Last Printed User Name 19 • • • • • • • •
  20. 20. 3. MIGRATION 20 • The transfer of a bit stream (the 1s and 0s) from one medium to another.
  21. 21. 21 FINDING THE HARDWARE
  22. 22. MIGRATION Similar to photocopying – including the imperfections. 22 Data can be lost or corrupted in the transfer.
  23. 23. WRITE BLOCKERS • Prevents inadvertently overwriting digital information. 23 • Allows „read‟ commands to pass, blocks „write‟ commands.
  24. 24. 4. EMULATION Creates an environment that „tricks‟ the software into functioning as if it was in its original computing environment. 24 Similar to impersonation.
  25. 25. EMULATION & THE GAMING COMMUNITY "The Old Version Flickers More": Digital Preservation from the User's Perspective 25 http://archivists.metapress.com/content/1765364485n41800/
  26. 26. https://archive.org/details/historicalsoftware 26 BROWSER BASED EMULATION
  27. 27. 5. HASHING/CHECKSUMS How they work: An algorithms „reads‟ a digital object and, based upon the 1s and 0s that make up that object, produces a unique alphanumeric string of characters that represent it. 27 What that means: Checksums are very effective tools in determining if a digital object has been corrupted (assuming you have the original checksum to compare it to).
  28. 28. HASHING MD5 Hash Corrupted File FD7D5993 062D270F 482E00BD E64D35FE 461D5E8093 B94401EAF 12E442CEA B908 28 Original File
  29. 29. http://download.cnet.com/MD5-SHA-Checksum-Utility/3000-2092_410911445.html 29 HASHING
  30. 30. 30 HASHING IN TWO STEPS
  31. 31. IDENTIFYING MYSTERY FILES .hqx? .mkv? .ape? 31 You have to identify what a file is in order to figure out what software can render it. But how?
  32. 32. 6. FILE IDENTIFICATION 32 Step 1: Google the file extension
  33. 33. 33 IDENTIFYING MYSTERY FILES
  34. 34. IDENTIFYING MYSTERY FILES Step 1: Google the file extension 34 Step 2: If step 1 fails, use DROID
  35. 35. http://www.nationalarchives.gov.uk/information-management/our-services/dc-file-profiling-tool.htm 35 Digital Record Object Identification
  36. 36. IDENTIFYING MYSTERY FILES Step 1: Google the file extension Step 2: If step 1 fails, use DROID 36 Step 3: If step 2 fails, open it in a hex editor
  37. 37. HXD HEX EDITOR 37 http://download.cnet.com/HxD-Hex-Editor/3000-2352_4-10891068.html
  38. 38. 38 HEX EDITOR VIEW
  39. 39. FILE SIGNATURES/MAGIC NUMBERS • Every file type has a digital „finger print‟ near the beginning of its code, sometimes called a „signature‟ or „magic number‟. 39 • In a hex editor, you can read the hexadecimal notation of the file and identify its magic number, then look up that number to identify the file type.
  40. 40. WIKIPEDIA’S FILE SIGNATURE LIST 40 http://en.wikipedia.org/wiki/List_of_file_signatures
  41. 41. IF YOU HAVE QUESTIONS ABOUT DIGITAL PRESERVATION 41 THE LIBRARY IS HERE TO HELP
  42. 42. Questions? Shea Swauger Data Management Librarian Morgan Library, 210E shea.swauger@gmail.com 42 This presentation is available at http://www.slideshare.net/SheaSwauger

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