1. Is this a positive or a negative number?
0000 0000 1000 1000 1101 1000 1111 0010 1100 0010 0100 0000 1110 1000 1011 1111 is the binary representation of a positive integer, on 64 bits (8 Bytes).
In a signed binary in one's complement representation, the first bit (the leftmost) indicates the sign, 1 = negative, 0 = positive.
2. Get the binary representation of the positive (unsigned) number.
* Run this step only if the number is negative *
Flip all the bits of the signed binary in one's complement representation (reverse the digits) - replace the bits set on 1 with 0s and the bits on 0 with 1s:
* Not the case - the number is positive *
3. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
263
0 262
0 261
0 260
0 259
0 258
0 257
0 256
0 255
1 254
0 253
0 252
0 251
1 250
0 249
0 248
0 247
1 246
1 245
0 244
1 243
1 242
0 241
0 240
0 239
1 238
1 237
1 236
1 235
0 234
0 233
1 232
0 231
1 230
1 229
0 228
0 227
0 226
0 225
1 224
0 223
0 222
1 221
0 220
0 219
0 218
0 217
0 216
0 215
1 214
1 213
1 212
0 211
1 210
0 29
0 28
0 27
1 26
0 25
1 24
1 23
1 22
1 21
1 20
1
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0000 0000 1000 1000 1101 1000 1111 0010 1100 0010 0100 0000 1110 1000 1011 1111(2) =
(0 × 263 + 0 × 262 + 0 × 261 + 0 × 260 + 0 × 259 + 0 × 258 + 0 × 257 + 0 × 256 + 1 × 255 + 0 × 254 + 0 × 253 + 0 × 252 + 1 × 251 + 0 × 250 + 0 × 249 + 0 × 248 + 1 × 247 + 1 × 246 + 0 × 245 + 1 × 244 + 1 × 243 + 0 × 242 + 0 × 241 + 0 × 240 + 1 × 239 + 1 × 238 + 1 × 237 + 1 × 236 + 0 × 235 + 0 × 234 + 1 × 233 + 0 × 232 + 1 × 231 + 1 × 230 + 0 × 229 + 0 × 228 + 0 × 227 + 0 × 226 + 1 × 225 + 0 × 224 + 0 × 223 + 1 × 222 + 0 × 221 + 0 × 220 + 0 × 219 + 0 × 218 + 0 × 217 + 0 × 216 + 1 × 215 + 1 × 214 + 1 × 213 + 0 × 212 + 1 × 211 + 0 × 210 + 0 × 29 + 0 × 28 + 1 × 27 + 0 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 1 × 20)(10) =
(0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 36 028 797 018 963 968 + 0 + 0 + 0 + 2 251 799 813 685 248 + 0 + 0 + 0 + 140 737 488 355 328 + 70 368 744 177 664 + 0 + 17 592 186 044 416 + 8 796 093 022 208 + 0 + 0 + 0 + 549 755 813 888 + 274 877 906 944 + 137 438 953 472 + 68 719 476 736 + 0 + 0 + 8 589 934 592 + 0 + 2 147 483 648 + 1 073 741 824 + 0 + 0 + 0 + 0 + 33 554 432 + 0 + 0 + 4 194 304 + 0 + 0 + 0 + 0 + 0 + 0 + 32 768 + 16 384 + 8 192 + 0 + 2 048 + 0 + 0 + 0 + 128 + 0 + 32 + 16 + 8 + 4 + 2 + 1)(10) =
(36 028 797 018 963 968 + 2 251 799 813 685 248 + 140 737 488 355 328 + 70 368 744 177 664 + 17 592 186 044 416 + 8 796 093 022 208 + 549 755 813 888 + 274 877 906 944 + 137 438 953 472 + 68 719 476 736 + 8 589 934 592 + 2 147 483 648 + 1 073 741 824 + 33 554 432 + 4 194 304 + 32 768 + 16 384 + 8 192 + 2 048 + 128 + 32 + 16 + 8 + 4 + 2 + 1)(10) =
38 519 133 985 368 255(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0000 0000 1000 1000 1101 1000 1111 0010 1100 0010 0100 0000 1110 1000 1011 1111(2) = 38 519 133 985 368 255(10)
The signed binary number in one's complement representation 0000 0000 1000 1000 1101 1000 1111 0010 1100 0010 0100 0000 1110 1000 1011 1111(2) converted and written as an integer in decimal system (base ten):
0000 0000 1000 1000 1101 1000 1111 0010 1100 0010 0100 0000 1110 1000 1011 1111(2) = 38 519 133 985 368 255(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.