1. Is this a positive or a negative number?
0011 1111 1011 1111 0111 1100 1110 1101 1001 0001 0110 1000 0111 0010 1011 0000 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
1 260
1 259
1 258
1 257
1 256
1 255
1 254
0 253
1 252
1 251
1 250
1 249
1 248
1 247
0 246
1 245
1 244
1 243
1 242
1 241
0 240
0 239
1 238
1 237
1 236
0 235
1 234
1 233
0 232
1 231
1 230
0 229
0 228
1 227
0 226
0 225
0 224
1 223
0 222
1 221
1 220
0 219
1 218
0 217
0 216
0 215
0 214
1 213
1 212
1 211
0 210
0 29
1 28
0 27
1 26
0 25
1 24
1 23
0 22
0 21
0 20
0
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0011 1111 1011 1111 0111 1100 1110 1101 1001 0001 0110 1000 0111 0010 1011 0000(2) =
(0 × 263 + 0 × 262 + 1 × 261 + 1 × 260 + 1 × 259 + 1 × 258 + 1 × 257 + 1 × 256 + 1 × 255 + 0 × 254 + 1 × 253 + 1 × 252 + 1 × 251 + 1 × 250 + 1 × 249 + 1 × 248 + 0 × 247 + 1 × 246 + 1 × 245 + 1 × 244 + 1 × 243 + 1 × 242 + 0 × 241 + 0 × 240 + 1 × 239 + 1 × 238 + 1 × 237 + 0 × 236 + 1 × 235 + 1 × 234 + 0 × 233 + 1 × 232 + 1 × 231 + 0 × 230 + 0 × 229 + 1 × 228 + 0 × 227 + 0 × 226 + 0 × 225 + 1 × 224 + 0 × 223 + 1 × 222 + 1 × 221 + 0 × 220 + 1 × 219 + 0 × 218 + 0 × 217 + 0 × 216 + 0 × 215 + 1 × 214 + 1 × 213 + 1 × 212 + 0 × 211 + 0 × 210 + 1 × 29 + 0 × 28 + 1 × 27 + 0 × 26 + 1 × 25 + 1 × 24 + 0 × 23 + 0 × 22 + 0 × 21 + 0 × 20)(10) =
(0 + 0 + 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 + 4 503 599 627 370 496 + 2 251 799 813 685 248 + 1 125 899 906 842 624 + 562 949 953 421 312 + 281 474 976 710 656 + 0 + 70 368 744 177 664 + 35 184 372 088 832 + 17 592 186 044 416 + 8 796 093 022 208 + 4 398 046 511 104 + 0 + 0 + 549 755 813 888 + 274 877 906 944 + 137 438 953 472 + 0 + 34 359 738 368 + 17 179 869 184 + 0 + 4 294 967 296 + 2 147 483 648 + 0 + 0 + 268 435 456 + 0 + 0 + 0 + 16 777 216 + 0 + 4 194 304 + 2 097 152 + 0 + 524 288 + 0 + 0 + 0 + 0 + 16 384 + 8 192 + 4 096 + 0 + 0 + 512 + 0 + 128 + 0 + 32 + 16 + 0 + 0 + 0 + 0)(10) =
(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 + 4 503 599 627 370 496 + 2 251 799 813 685 248 + 1 125 899 906 842 624 + 562 949 953 421 312 + 281 474 976 710 656 + 70 368 744 177 664 + 35 184 372 088 832 + 17 592 186 044 416 + 8 796 093 022 208 + 4 398 046 511 104 + 549 755 813 888 + 274 877 906 944 + 137 438 953 472 + 34 359 738 368 + 17 179 869 184 + 4 294 967 296 + 2 147 483 648 + 268 435 456 + 16 777 216 + 4 194 304 + 2 097 152 + 524 288 + 16 384 + 8 192 + 4 096 + 512 + 128 + 32 + 16)(10) =
4 593 527 504 729 830 064(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0011 1111 1011 1111 0111 1100 1110 1101 1001 0001 0110 1000 0111 0010 1011 0000(2) = 4 593 527 504 729 830 064(10)
The signed binary number in one's complement representation 0011 1111 1011 1111 0111 1100 1110 1101 1001 0001 0110 1000 0111 0010 1011 0000(2) converted and written as an integer in decimal system (base ten):
0011 1111 1011 1111 0111 1100 1110 1101 1001 0001 0110 1000 0111 0010 1011 0000(2) = 4 593 527 504 729 830 064(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.