1. Is this a positive or a negative number?
0111 1111 1010 0011 1100 0000 0011 0110 1010 1111 0100 0110 1110 0000 0001 0011 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
1 261
1 260
1 259
1 258
1 257
1 256
1 255
1 254
0 253
1 252
0 251
0 250
0 249
1 248
1 247
1 246
1 245
0 244
0 243
0 242
0 241
0 240
0 239
0 238
0 237
1 236
1 235
0 234
1 233
1 232
0 231
1 230
0 229
1 228
0 227
1 226
1 225
1 224
1 223
0 222
1 221
0 220
0 219
0 218
1 217
1 216
0 215
1 214
1 213
1 212
0 211
0 210
0 29
0 28
0 27
0 26
0 25
0 24
1 23
0 22
0 21
1 20
1
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0111 1111 1010 0011 1100 0000 0011 0110 1010 1111 0100 0110 1110 0000 0001 0011(2) =
(0 × 263 + 1 × 262 + 1 × 261 + 1 × 260 + 1 × 259 + 1 × 258 + 1 × 257 + 1 × 256 + 1 × 255 + 0 × 254 + 1 × 253 + 0 × 252 + 0 × 251 + 0 × 250 + 1 × 249 + 1 × 248 + 1 × 247 + 1 × 246 + 0 × 245 + 0 × 244 + 0 × 243 + 0 × 242 + 0 × 241 + 0 × 240 + 0 × 239 + 0 × 238 + 1 × 237 + 1 × 236 + 0 × 235 + 1 × 234 + 1 × 233 + 0 × 232 + 1 × 231 + 0 × 230 + 1 × 229 + 0 × 228 + 1 × 227 + 1 × 226 + 1 × 225 + 1 × 224 + 0 × 223 + 1 × 222 + 0 × 221 + 0 × 220 + 0 × 219 + 1 × 218 + 1 × 217 + 0 × 216 + 1 × 215 + 1 × 214 + 1 × 213 + 0 × 212 + 0 × 211 + 0 × 210 + 0 × 29 + 0 × 28 + 0 × 27 + 0 × 26 + 0 × 25 + 1 × 24 + 0 × 23 + 0 × 22 + 1 × 21 + 1 × 20)(10) =
(0 + 4 611 686 018 427 387 904 + 2 305 843 009 213 693 952 + 1 152 921 504 606 846 976 + 576 460 752 303 423 488 + 288 230 376 151 711 744 + 144 115 188 075 855 872 + 72 057 594 037 927 936 + 36 028 797 018 963 968 + 0 + 9 007 199 254 740 992 + 0 + 0 + 0 + 562 949 953 421 312 + 281 474 976 710 656 + 140 737 488 355 328 + 70 368 744 177 664 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 137 438 953 472 + 68 719 476 736 + 0 + 17 179 869 184 + 8 589 934 592 + 0 + 2 147 483 648 + 0 + 536 870 912 + 0 + 134 217 728 + 67 108 864 + 33 554 432 + 16 777 216 + 0 + 4 194 304 + 0 + 0 + 0 + 262 144 + 131 072 + 0 + 32 768 + 16 384 + 8 192 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 16 + 0 + 0 + 2 + 1)(10) =
(4 611 686 018 427 387 904 + 2 305 843 009 213 693 952 + 1 152 921 504 606 846 976 + 576 460 752 303 423 488 + 288 230 376 151 711 744 + 144 115 188 075 855 872 + 72 057 594 037 927 936 + 36 028 797 018 963 968 + 9 007 199 254 740 992 + 562 949 953 421 312 + 281 474 976 710 656 + 140 737 488 355 328 + 70 368 744 177 664 + 137 438 953 472 + 68 719 476 736 + 17 179 869 184 + 8 589 934 592 + 2 147 483 648 + 536 870 912 + 134 217 728 + 67 108 864 + 33 554 432 + 16 777 216 + 4 194 304 + 262 144 + 131 072 + 32 768 + 16 384 + 8 192 + 16 + 2 + 1)(10) =
9 197 406 205 122 109 459(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0111 1111 1010 0011 1100 0000 0011 0110 1010 1111 0100 0110 1110 0000 0001 0011(2) = 9 197 406 205 122 109 459(10)
The signed binary number in one's complement representation 0111 1111 1010 0011 1100 0000 0011 0110 1010 1111 0100 0110 1110 0000 0001 0011(2) converted and written as an integer in decimal system (base ten):
0111 1111 1010 0011 1100 0000 0011 0110 1010 1111 0100 0110 1110 0000 0001 0011(2) = 9 197 406 205 122 109 459(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.