1. Is this a positive or a negative number?
0000 0000 0000 0000 0111 1000 0111 0101 0000 0011 1001 0100 1000 0100 0111 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
0 254
0 253
0 252
0 251
0 250
0 249
0 248
0 247
0 246
1 245
1 244
1 243
1 242
0 241
0 240
0 239
0 238
1 237
1 236
1 235
0 234
1 233
0 232
1 231
0 230
0 229
0 228
0 227
0 226
0 225
1 224
1 223
1 222
0 221
0 220
1 219
0 218
1 217
0 216
0 215
1 214
0 213
0 212
0 211
0 210
1 29
0 28
0 27
0 26
1 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 0000 0000 0111 1000 0111 0101 0000 0011 1001 0100 1000 0100 0111 1111(2) =
(0 × 263 + 0 × 262 + 0 × 261 + 0 × 260 + 0 × 259 + 0 × 258 + 0 × 257 + 0 × 256 + 0 × 255 + 0 × 254 + 0 × 253 + 0 × 252 + 0 × 251 + 0 × 250 + 0 × 249 + 0 × 248 + 0 × 247 + 1 × 246 + 1 × 245 + 1 × 244 + 1 × 243 + 0 × 242 + 0 × 241 + 0 × 240 + 0 × 239 + 1 × 238 + 1 × 237 + 1 × 236 + 0 × 235 + 1 × 234 + 0 × 233 + 1 × 232 + 0 × 231 + 0 × 230 + 0 × 229 + 0 × 228 + 0 × 227 + 0 × 226 + 1 × 225 + 1 × 224 + 1 × 223 + 0 × 222 + 0 × 221 + 1 × 220 + 0 × 219 + 1 × 218 + 0 × 217 + 0 × 216 + 1 × 215 + 0 × 214 + 0 × 213 + 0 × 212 + 0 × 211 + 1 × 210 + 0 × 29 + 0 × 28 + 0 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 1 × 20)(10) =
(0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 70 368 744 177 664 + 35 184 372 088 832 + 17 592 186 044 416 + 8 796 093 022 208 + 0 + 0 + 0 + 0 + 274 877 906 944 + 137 438 953 472 + 68 719 476 736 + 0 + 17 179 869 184 + 0 + 4 294 967 296 + 0 + 0 + 0 + 0 + 0 + 0 + 33 554 432 + 16 777 216 + 8 388 608 + 0 + 0 + 1 048 576 + 0 + 262 144 + 0 + 0 + 32 768 + 0 + 0 + 0 + 0 + 1 024 + 0 + 0 + 0 + 64 + 32 + 16 + 8 + 4 + 2 + 1)(10) =
(70 368 744 177 664 + 35 184 372 088 832 + 17 592 186 044 416 + 8 796 093 022 208 + 274 877 906 944 + 137 438 953 472 + 68 719 476 736 + 17 179 869 184 + 4 294 967 296 + 33 554 432 + 16 777 216 + 8 388 608 + 1 048 576 + 262 144 + 32 768 + 1 024 + 64 + 32 + 16 + 8 + 4 + 2 + 1)(10) =
132 443 966 571 647(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0000 0000 0000 0000 0111 1000 0111 0101 0000 0011 1001 0100 1000 0100 0111 1111(2) = 132 443 966 571 647(10)
The signed binary number in one's complement representation 0000 0000 0000 0000 0111 1000 0111 0101 0000 0011 1001 0100 1000 0100 0111 1111(2) converted and written as an integer in decimal system (base ten):
0000 0000 0000 0000 0111 1000 0111 0101 0000 0011 1001 0100 1000 0100 0111 1111(2) = 132 443 966 571 647(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.