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Looking Inside the Black Box

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Presentation on theme: "Looking Inside the Black Box"— Presentation transcript:

1 Looking Inside the Black Box
Input Output CPU Storage Secondary - Hard Drives Primary - RAM, ROM

2 Storing Data Computers store Digital Data Two type of data
Digital – can be compressed Analog Digital data – stored as digital data Text data – stored as ASCII codes (digital) Analog data – converted to digital

3 Storing Data – Binary Numbers

4 Storing Data – Binary Numbers

5 Storing Data – Binary Numbers
Used to store digital data 8 bits 0 = 1 = 2 = ... 254 = 255 = 16 bits 0 = 1 = 2 = ... 65534 = 65535 =

6 Storing Data – Hexadecimal
Easy way to represent binary numbers Easy to convert between hex and binary Base 16 0 = 0000 1 = 0001 2 = 0010 3 = 0011 4 = 0100 5 = 0101 6 = 0110 7 = 0111 8 = 1000 9 = 1001 A = 1010 B = 1011 C = 1100 D = 1101 E = 1110 F = 1111

7 Storing Data – ASCII Used to store text based DIGIT 1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 ASCII REPRESENTATION LETTER A B C D E F G H I ASCII REPRESENTATION

8 32      blank      65       A         66       B         67       C         68       D         69       E         70       F         71       G         72       I         73       I         74       J         75       K         76       L         77       M         78       N         79       O         80       P         81       Q         82       R         83       S         84       T             97       a          98       b          99       c         100       d         101       e         102       f         103       g         104       h         105       i         106       j         107       k         108       l         109       m         110       n         111       o         112       p         113       q         114       r         115       s         116       t         117       u        

9 ASCII Full ASCII Table F o u r a n d s e v e n

10 Storing Data – Analog Data
Must be converted to Digital Sample demo

11 Converting Between Number Systems
Binary to Decimal Decimal to Binary Binary to Hex Hex to Binary

12 Converting Between Number Systems
Decimal Binary

13 Converting Between Number Systems
Binary >Decimal > decimal > decimal Decimal > Binary 128 > binary 100 > binary Hex > Binary 1A > binary 0F > binary Binary > Hex > hex > hex ASCII > Decimal A > decimal a > decimal Decimal > ASCII > ascii > ascii

14 Coding Data for Processing by a Computer
Pixels Data Compression Lossy - examples Lossless - examples ?Examples of file types

15 Data Compression Binary Data Compressed Data
\ 12 bytes Compressed Data 4, ,255 5 bytes

16 Compression Examples BMP (422kb)

17 Compression Examples JPG 10% (66kb)

18 Compression Examples JPG 85% (15kb)

19 Compression - LZ Lempel – Ziv WinZip
Dictionary to eliminate redundancy From - HowStuffWorks.com

20 Compression - LZ Example
"Ask not what your country can do for you -- ask what you can do for your country.“ = 79 chrs Dictionary: ask what your country can do for you “1 not " = 37 chrs From - HowStuffWorks.com

21 Compression - LZ Plus Dictionary = 37, Total = 74 vs 79
Real LZ uses patterns not words ask__ what__ you r__country __can__do__for__you "1not__ " = 16 chrs Dictionary = 41, Total = 57 From - HowStuffWorks.com


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