Hexadecimal

Hexadecimal or "Hex" for short, is a way of representing numbers. It is used in many programming codes.
Decimal is the system we usually use for numbers, this is a "base ten" system as it uses ten different numerals:

0, 1, 2, 3, 4, 5, 6, 7, 8 and 9

Similarly, hexadecimal is a base 16 system. ("hex" is Latin for six, "deci" is Latin for ten) It uses the ten numerals used by the decimal system, plus the first six letters of the alphabet.

You'll notice that the first nine numbers are identical in decimal and hex, but then instead of moving on to two digits, hex uses the six letters first to represent the decimal numbers 10 to 15. You can quickly see the advantage of hexadecimal, it condenses the volume of data considerably. In fact ALL the 256 numbers used by Creatures are all two digit in hex.

Also in the table is the ASCII code, useful for hex editing. The green ones at the begginning are acronyms of the command triggered rather than a character.
HEX  DECIMAL ASCII   HEX  DECIMAL ASCII   HEX  DECIMAL ASCII   HEX  DECIMAL ASCII   HEX  DECIMALASCII
0 0 null32 50 264 100 d96 150 C8 200
1 1 soh33 51 365 101 e97 151 C9 201
2 2 stx34 52 466 102 f98 152 CA 202
3 3 etx35 53 567 103 g99 153 CB 203
4 4 eot36 54 668 104 h9A 154 CC 204
5 5 enq37 55 769 105 i9B 155 CD 205
6 6 ack38 56 86A 106 j9C 156 CE 206
7 7 bel39 57 96B 107 k9D 157 CF 207
8 8 bs3A 58 :6C 108 l9E 158 D0 208
9 9 tab3B 59 ;6D 109 m9F 159 D1 209
A 10 lf3C 60 <6E 110 nA0 160 D2 210
B 11 vt3D 61 =6F 111 oA1 161 D3 211
C 12 ff3E 62 >70 112 pA2 162 D4 212
D 13 cr3F 63 ?71 113 qA3 163 D5 213
E 14 so40 64 @72 114 rA4 164 D6 214
F 15 si41 65 A73 115 sA5 165 D7 215
10 16 dle42 66 B74 116 tA6 166 D8 216
11 17 dc143 67 C75 117 uA7 167 D9 217
12 18 dc244 68 D76 118 vA8 168 DA 218
13 19 dc345 69 E77 119 wA9 169 DB 219
14 20 dc446 70 F78 120 xAA 170 DC 220
15 21 nak47 71 G79 121 yAB 171 DD 221
16 22 syn48 72 H7A 122 zAC 172 DE 222
17 23 etb49 73 I7B 123 {AD 173 DF 223
18 24 can4A 74 J7C 124 |AE 174 E0 224
19 25 em4B 75 K7D 125 }AF 175 E1 225
1A26sub4C76L7E126~B0176E2226
1B 27 esc4D 77 M7F 127 delB1 177 E3 227
1C 28 fs4E 78 N80 128 B2 178 E4 228
1D 29 gs4F 79 O81 129 B3 179 E5 229
1E 30 rs50 80 P82 130 ,B4 180 E6 230
1F 31 us51 81 Q83 131 B5 181 E7 231
20 32 space52 82 R84 132 B6 182 E8 232
21 33 !53 83 S85 133 B7 183 E9 233
22 34 "54 84 T86 134 B8 184 EA 234
23 35 #55 85 U87 135 B9 185 EB 235
24 36 $56 86 V88 136 BA 186 EC 236
25 37 %57 87 W89 137 BB 187 ED 237
26 38 &58 88 X8A 138 BC 188 EE 238
27 39 '59 89 Y8B 139 BD 189 EF 239
28 40 (5A 90 Z8C 140 BE 190 F0 240
29 41 )5B 91 [8D 141 BF 191 F1 241
2A 42 *5C 92 \8E 142 C0 192 F2 242
2B 43 +5D 93 ]8F 143 C1 193 F3 243
2C 44 ,5E 94 ^90 144 C2 194 F4 244
2D 45 -5F 95 _91 145 C3 195 F5 245
2E 46 .60 96 `92 146 C4 196 F6 246
2F 47 /61 97 a93 147 C5 197 F7 247
30 48 062 98 b94 148 C6 198 F8 248
31 49 163 99 c95 149 C7 199 F9 249
FA 250
FB 251
FC 252
FD 253
FE 254
FF 255

Here seems a good place to mention binary. As you may or may not know, a computer runs, at its most basic level on 1s and 0s. Representing pulses of electricity in the circuitry.
Binary is a base 2 system, with only two numerals: 1 and 0.

In computer lingo, a single digit in a binary number is called a bit, eight bits make up a byte e.g. 01010011.
Each byte can represent the numbers from 0 all the way up to 255, this is why we use hexadecimal to easily manipulate code, as it can represent bytes as 2 digits instead of 8.

Hexadecimal Binary Decimal
0 0 0
1 1 1
2 10 2
3 11 3
4 100 4
5 101 5
6 110 6
7 111 7
8 1000 8
9 1001 9
A 1010 10
B 1011 11
C 1100 12
D 1101 13
E 1110 14
F 1111 15
10 10000 16
11 10001 17