Computer change the world

Objective:

when i could see the video, i have some learned about this. To how computer works, and how computer systematically operate.

Summary:

The video of computer change the world is to define how computer starts and how computer very important in our lives. Because when you see the past several years there was many things are slow and delayed processing. Because of manual use and lack of technology. After several years the computer is invented,because of high ability to fast access, fast moving works, and easy to handle of heavy things. Etc., and the micro chip. micro chip is very important thing not only computer but use this any other devices. Micro chip is too little but can function all devices.

Conclusion:

The computer is the system can access all you needs. Like program. make a website. research and more.

Hexadecimal numbers

A Brief Explanation
of Hexadecimal Numbers-

SAY WHAT?

When you are working with computers, and especially the Internet and the Web, you will eventually run into things like the above - - - Hexadecimal (HEX) Numbers.

The following will not pretend to make you a Hex math genius, but we will explain just what those funny letters mean.

When people evolved, they did so with ten fingers. (Yes we do have a few folks down in Horsepasture with 11 fingers and 12 toes, but that's social commentary, not math.)

Since we have ten fingers, and since early man probably used them as the first counting device, we learned to count in TENs. DECI, Latin for Ten, gave birth to the term DECImal.

Decimal numbers are based on POWERS of Ten.

1 x 10 = 10 10 x 10 = 100, 10 x 10 x 10 = 1,000 etc.

Since everything is based on Tens, we only need Ten Digits to represent every possible number.

1, 2, 3, 4, 5, 6, 7, 8, 9, 0
Note: The Romans had no number for, or possibly even the concept of Zero

So, let's start counting up from Zero in Decimal . . .

0 - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - OOPS - We're Out of Digits!

Since we ran out of digits, we need to do a bit of trickery to represent numbers higher than 9. What we do is start over with Zero as the rightmost digit, and put a One (1) to it's left. ---- 10 - 11 - 12 ... 18 - 19 - 20 - etc.

The "Decimal Place Holders" are all Powers of Ten

The rightmost digit tells us how many ONES are in the number.

The next digit to the left tells us how many TENS, the next, how many HUNDREDS, etc. Take the number 14, 728

How the Brain Decodes a Decimal Number

Powers of Ten 10,000s 1,000s 100's 10's Ones 1 4 7 2 8

To "Decode" this number, the brain subconsiously goes . . .

There is one Ten Thousand, Four One Thousands,
Seven One Hundreds, Two Tens and Eight Ones
Add them all together and you get 14,728

10,000	x	1	=	10,000
1,000	x	4	=	4,000
100	x	7	=	700
10	x	2	=	20
8	x	1	=	8
			+
14, 728

That's how modern number systems work!

---

Now a fact, a question and a conclusion.

Fact: For reasons best left to people with Pocket Protectors and no personal skills, computers like to "Think" in 'groups' of EIGHT digits instead of Ten.

Question: What if people had evolved with Eight fingers per hand instead of Five?

Conclusion: We'd have developed a number system based on powers of Sixteen rather than powers of Ten

THAT is exactly what the HEXadecimal number system is, a number system based on 16's, not tens.

Let's start counting upwards from Zero in Hex . . .

1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - OOPS - Out of Digits again, but we don't do the add a Zero and scoot stuff over until we get to 16.

Where do you get the additional digits?
You Dont -- You Use Letters!

Dec	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	...	24	25	26	27
Hex	0	1	2	3	4	5	6	7	8	9	A	B	C	D	E	F	10	11	12	13	14	...	18	19	1A	1B

Let's Decode the Hex Number F2A4C= 993,868

Powers of 16 65,536's 4096's 256's 16's Ones F 2 A 4 C

To "Decode" this number, the NERD BRAIN
(Or Calculator More Likely) consciously thinks . . .

65,536	x	F	=	983,040
4,096	x	2	=	8,192
256	x	A	=	2,560
16	x	4	=	64
1	x	C	=	12
			+
993,868

IF YOU'RE LOST,
DON'T FRET OVER IT!

There's no real need for you to take pencil in hand to figure this stuff out.
IF you ever need to, you'll find handy Hex/Decimal calculators are supplied with both Windows and the Mac OS.

Also, at the moment, it's only important that you have a passing familiarity with this (and the Binary - Powers of Two) number system.

Let's Examine a Typical Browser Color Code.

FF33CC">

In our discussion of Hexadecimal Color Codes we explained that the above is called a TRIPLET, or group of THREE Numbers. (FF, 33 and cc)

Colors are specified by how much RED (from Zero to 255), Green (from Zero to 255) and Blue (from Zero to 255) are in the final color.

We must, however, specify these color values in Hex.

FF 33 CC Is Therefore . . .

FF (Hex) = 255 (Decimal) Points of Red
33 (Hex) = 51 (Decimal) Poinrs of Green
CC (Hex) = 204 (Decimal) Points of Blue

The Result Is This Color

Again please let me state that in the beginning, a passing familiarity with these number systems is all you need. At least you should no longer be intimidated when some piece of software asks you to enter something in Hex.

Interesting Fact: The fact that computers use alternate number systems explains why 1K (1000) in Computerese is REALLY 1,024 and 4K (4000) is Really 4,096. We're NOT working with even powers of Ten, but powers of Two.

Here Is A Handy Hex to Decimal and Binary Conversion Chart

The octal number system

Just as the decimal system with its ten digits is a base-ten system, the octal number system with its 8 digits, ‘0’, ‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’ and ‘7’, is a base-eight system. Table 2-4 shows the weighting for the octal number system up to 3 decimal places before and 2 decimal places after the octal point (.).

Weights

82

81

80

.

8-1

8-2

Table 2-4 Octal Weights

Just like the other counting conventions discussed previously, the LSB is begins with zero (0) and is incremented until the maximum digit value is reached. The adjacent bit positions are then filled appropriately as the iterative counting process continues. Thus the counting convention for octal is 0,1,2,3,4,5,7,10,11,12,13,14,15,16,17,20….

Conversion from Octal to Decimal

To express the value of a given octal number as its decimal equivalent we just need to sum the digits after each has been multiplied by its associated weight.

Example #1

Convert (237.04) ₈ to decimal form.

Weights	82	81	80	8-1	8-2
Weight Value	64	8	1	0.125	0.015625
Octal Number	2	3	7	0	4
Decimal Value	128	24	7	0	0.0625	Total (159.0625)10

Conversion from Decimal Whole Numbers to Octal

To convert from Decimal whole numbers to Octal we may use the systematic approach called the Repeated-Division-by-8 method shown in the example below.

Converting (359) ₁₀ to Octal

1. Divide the quotient by eight and record the remainder.

2. Repeat step (a) until the quotient is equal to zero (0).

3. The first remainder produced is the LSB in the octal number and the last remainder (R) the MSB. Accordingly, the octal number is then written (from left to right) with the MSB occurring first

8	359
8	44	R 7 (LSB)
8	5	R 4
8	0	R 5 (MSB)

Therefore, (359) ₁₀ = (547) ₈

Converting Decimal Fractions to Octal

The techniques used to convert decimal fractions to octal are similar to the methods demonstrated previously to convert decimal fractions to binary numbers. We may either use the sum-of–weights method or the repeated multiplication–by-8 method. In the multiplication–by-8 method we repeatedly multiply the fraction by eight, and record the carry, until the fraction product is zero. The first carry produced is the MSB, while the last carry is the LSM. Remember that the octal point precedes the MSB. To illustrate lets consider the conversion of (0.3125) ₁₀ to octal.

0.3125 * 8	Carry
0.5 * 8	2 (MSB)
0.0	4 (LSB)

thus, (0.3125) ₁₀ = (0.24) ₈

Converting Octal to Binary

The primary application of octal numbers is representing binary numbers, as it is easier to read large numbers in octal form that in binary form. Because each octal digit can be represented by a three-bit binary number (see Table 2-5), it is very easy to convert from octal to binary. Simply replace each octal digit with the appropriate three-bit binary number as indicated in the examples below.

Octal Digit	Binary Digit
0	000
1	001
2	010
3	011
4	100
5	101
6	110
7	111

Example #1 Table 2-5 Octal and Binary Numbers

Converting Binary to Octal

Converting binary to octal is also a simple process. Break the binary digits into groups of three starting from the binary point and convert each group into its appropriate octal digit. For whole numbers, it may be necessary to add a zero as the MSB in order to complete a grouping of three bits. Note that this does not change the value of the binary number. Similarly, when representing fractions, it may be necessary to add a trailing zero in the LSB in order to form a complete grouping of three.

Examples:

1. Converting (010111) ₂ to Octal

111 = 7 (LSB)

010 = 2 (MSB)

thus, (010111) ₂ = (27) ₈

2. Converting (0.110101) ₂ to Octal

110 = 6 (MSB)

111 = 5 (LSB)

thus, (0.110101) ₂ = (0.65) ₈

ASCII Code

Extended ASCII Codes
As people gradually required computers to understand additional characters and non-printing characters the ASCII set became restrictive. As with most technology, it took a while to get a single standard for these extra characters and hence there are few varying 'extended' sets. The most popular is presented below.

EBCDIC Code

Extended Binary Coded Decimal Interchange Code (EBCDIC)

is an 8-bit character encoding (code page) used on IBM mainframe operating systems such as z/OS, OS/390, VM and VSE, as well as IBM midrange computer operating systems such as OS/400 and i5/OS (see also Binary Coded Decimal). It is also employed on various non-IBM platforms such as Fujitsu-Siemens' BS2000/OSD, HP MPE/iX, and Unisys MCP. EBCDIC descended from the code used with punched cards and the corresponding six bit binary-coded decimal code used with most of IBM's computer peripherals of the late 1950s and early 1960s.

History

EBCDIC was devised in 1963 and 1964 by IBM and was announced with the release of the IBM System/360 line of mainframe computers. It was created to extend the Binary-Coded Decimal encoding that existed at the time. It is an 8-bit character encoding, in contrast to, and developed separately from, the 7-bit ASCII encoding scheme.

While IBM was a chief proponent of the ASCII standardization committee, they did not have time to prepare ASCII peripherals (such as card punch machines) to ship with its System/360 computers, so the company settled on EBCDIC at the time. The System/360 became wildly successful, and thus so did EBCDIC.

All IBM mainframe peripherals and operating systems (except Linux on zSeries or iSeries) use EBCDIC as their inherent encoding,^[1] but software can translate to and from other encodings. Many hardware peripherals provide translation as well and modern mainframes (such as IBM zSeries) include processor instructions, at the hardware level, to accelerate translation between character sets.

At the time it was devised, EBCDIC made it relatively easy to enter data into a computer with punch cards. Since punch cards are no longer used on mainframes, EBCDIC is used in modern mainframes primarily for backwards compatibility. It does have an advantage of limiting the number of hole punches per column to 2 holes for uppercase and numbers, which increases the durability of these punch cards as they are handled by a card reader. This encoding is also known as Hollerith code. ^[2]

EBCDIC has no modern technical advantage over ASCII-based code pages such as the ISO-8859 series or Unicode. There are some technical niceties in each, e.g., ASCII and EBCDIC both have one bit which indicates upper or lower case. But there are some aspects of EBCDIC which make it much less pleasant to work with than ASCII (such as a non-contiguous alphabet). As with single-byte extended ASCII codepages, most EBCDIC codepages only allow up to 2 languages (English and one other language) to be used in a database or text file.

Where true support for multilingual text is desired, a system supporting far more characters is needed. Generally this is done with some form of Unicode support. There is an EBCDIC Unicode Transformation Format called UTF-EBCDIC proposed by the Unicode consortium, but it is not intended to be used in open interchange environments and, even on EBCDIC-based systems, it is almost never used. IBM mainframes support UTF-16, but they do not support UTF-EBCDIC natively.

Arabic EBCDIC versions are typically in presentation order, in left to right order as displayed by an older mainframe or line printer, rather than in the right to left logical order used by modern encodings such as Unicode.

Code page layout

The table below is derived from CCSID 500, one of the code page variants of EBCDIC, showing only the basic (English) EBCDIC characters. Characters 00–3F and FF are controls, 40 is space, 41 is no-break space (RSP: "Required Space"), E1 is numeric space (NSP: "Numeric Space"), and CA is soft hyphen. Characters are shown with their equivalent Unicode codes. Invariant alphanumeric, punctuation, and control characters common to all EBCDIC code pages are shown in color. Unassigned codes are typically filled with international or region-specific characters in the various EBCDIC code page variants.

EBCDIC
	—0	—1	—2	—3	—4	—5	—6	—7	—8	—9	—A	—B	—C	—D	—E	—F
0−	NUL 0000 0	SOH 0001 1	STX 0002 2	ETX 0003 3	SEL 4	HT 0009 5	RNL 6	DEL 007F 7	GE 8	SPS 9	RPT 10	VT 000B 11	FF 000C 12	CR 000D 13	SO 000E 14	SI 000F 15
1−	DLE 0010 16	DC1 0011 17	DC2 0012 18	DC3 0013 19	RES ENP 20	NL 0085 21	BS 0008 22	POC 23	CAN 0018 24	EM 0019 25	UBS 26	CU1 27	IFS 001C 28	IGS 001D 29	IRS 001E 30	IUS ITB 001F 31
2−	DS 32	SOS 33	FS 34	WUS 35	BYP INP 36	LF 000A 37	ETB 0017 38	ESC 001B 39	SA 40	SFE 41	SM SW 42	CSP 43	MFA 44	ENQ 0005 45	ACK 0006 46	BEL 0007 47
3−	48	49	SYN 0016 50	IR 51	PP 52	TRN 53	NBS 54	EOT 0004 55	SBS 56	IT 57	RFF 58	CU3 59	DC4 0014 60	NAK 0015 61	62	SUB 001A 63
4−	SP 0020 64	RSP 00A0 65	66	67	68	69	70	71	72	73	74	. 002E 75	< 003C 76	( 0028 77	+ 002B 78	| 007C 79
5−	& 0026 80	81	82	83	84	85	86	87	88	89	! 0021 90	$ 0024 91	* 002A 92	) 0029 93	; 003B 94	¬ 00AC 95
6−	- 002D 96	/ 002F 97	98	99	100	101	102	103	104	105	¦ 00A6 106	, 002C 107	% 0025 108	_ 005F 109	> 003E 110	? 003F 111
7−	112	113	114	115	116	117	118	119	120	` 0060 121	: 003A 122	# 0023 123	@ 0040 124	' 0027 125	= 003D 126	" 0022 127
8−	128	a 0061 129	b 0062 130	c 0063 131	d 0064 132	e 0065 133	f 0066 134	g 0067 135	h 0068 136	i 0069 137	138	139	140	141	142	± 00B1 143
9−	144	j 006A 145	k 006B 146	l 006C 147	m 006D 148	n 006E 149	o 006F 150	p 0070 151	q 0071 152	r 0072 153	154	155	156	157	158	159
A−	160	~ 007E 161	s 0073 162	t 0074 163	u 0075 164	v 0076 165	w 0077 166	x 0078 167	y 0079 168	z 007A 169	170	171	172	173	174	175
B−	^ 005E 176	177	178	179	180	181	182	183	184	185	[ 005B 186	] 005D 187	188	189	190	191
C−	{ 007B 192	A 0041 193	B 0042 194	C 0043 195	D 0044 196	E 0045 197	F 0046 198	G 0047 199	H 0048 200	I 0049 201	SHY 00AD 202	203	204	205	206	207
D−	} 007D 208	J 004A 209	K 004B 210	L 004C 211	M 004D 212	N 004E 213	O 004F 214	P 0050 215	Q 0051 216	R 0052 217	218	219	220	221	222	223
E−	\ 005C 224	225	S 0053 226	T 0054 227	U 0055 228	V 0056 229	W 0057 230	X 0058 231	Y 0059 232	Z 005A 233	234	235	236	237	238	239
F−	0 0030 240	1 0031 241	2 0032 242	3 0033 243	4 0034 244	5 0035 245	6 0036 246	7 0037 247	8 0038 248	9 0039 249	250	251	252	253	254	EO 255
	—0	—1	—2	—3	—4	—5	—6	—7	—8	—9	—A	—B	—C	—D	—E	—F

Criticism and humor

Open-source-software advocate and hacker Eric S. Raymond writes in his Jargon File that EBCDIC was almost universally loathed by early hackers and programmers because of its multitude of different versions, none of which resembled the other versions, and that IBM produced it in direct competition with the already-established ASCII.

Another popular complaint is that the EBCDIC alphabetic characters follow an archaic punch card encoding rather than a linear ordering like ASCII. One consequence of this is that incrementing the character code for "I" does not produce the code for "J", and likewise there is a gap between the codes for "R" and "S". Thus programming a simple control loop to cycle through only the alphabetic characters is problematic.