What are the steps to convert the signed binary in one's (1's) complement representation to an integer in decimal system (in base ten)?
1. Is this a positive or a negative number?
0100 0101 0000 0000 0000 0000 0010 1001 1101 1011 1111 1011 0011 1111 1111 0101 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
0 260
0 259
0 258
1 257
0 256
1 255
0 254
0 253
0 252
0 251
0 250
0 249
0 248
0 247
0 246
0 245
0 244
0 243
0 242
0 241
0 240
0 239
0 238
0 237
1 236
0 235
1 234
0 233
0 232
1 231
1 230
1 229
0 228
1 227
1 226
0 225
1 224
1 223
1 222
1 221
1 220
1 219
1 218
0 217
1 216
1 215
0 214
0 213
1 212
1 211
1 210
1 29
1 28
1 27
1 26
1 25
1 24
1 23
0 22
1 21
0 20
1
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0100 0101 0000 0000 0000 0000 0010 1001 1101 1011 1111 1011 0011 1111 1111 0101(2) =
(0 × 263 + 1 × 262 + 0 × 261 + 0 × 260 + 0 × 259 + 1 × 258 + 0 × 257 + 1 × 256 + 0 × 255 + 0 × 254 + 0 × 253 + 0 × 252 + 0 × 251 + 0 × 250 + 0 × 249 + 0 × 248 + 0 × 247 + 0 × 246 + 0 × 245 + 0 × 244 + 0 × 243 + 0 × 242 + 0 × 241 + 0 × 240 + 0 × 239 + 0 × 238 + 1 × 237 + 0 × 236 + 1 × 235 + 0 × 234 + 0 × 233 + 1 × 232 + 1 × 231 + 1 × 230 + 0 × 229 + 1 × 228 + 1 × 227 + 0 × 226 + 1 × 225 + 1 × 224 + 1 × 223 + 1 × 222 + 1 × 221 + 1 × 220 + 1 × 219 + 0 × 218 + 1 × 217 + 1 × 216 + 0 × 215 + 0 × 214 + 1 × 213 + 1 × 212 + 1 × 211 + 1 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 1 × 20)(10) =
(0 + 4 611 686 018 427 387 904 + 0 + 0 + 0 + 288 230 376 151 711 744 + 0 + 72 057 594 037 927 936 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 137 438 953 472 + 0 + 34 359 738 368 + 0 + 0 + 4 294 967 296 + 2 147 483 648 + 1 073 741 824 + 0 + 268 435 456 + 134 217 728 + 0 + 33 554 432 + 16 777 216 + 8 388 608 + 4 194 304 + 2 097 152 + 1 048 576 + 524 288 + 0 + 131 072 + 65 536 + 0 + 0 + 8 192 + 4 096 + 2 048 + 1 024 + 512 + 256 + 128 + 64 + 32 + 16 + 0 + 4 + 0 + 1)(10) =
(4 611 686 018 427 387 904 + 288 230 376 151 711 744 + 72 057 594 037 927 936 + 137 438 953 472 + 34 359 738 368 + 4 294 967 296 + 2 147 483 648 + 1 073 741 824 + 268 435 456 + 134 217 728 + 33 554 432 + 16 777 216 + 8 388 608 + 4 194 304 + 2 097 152 + 1 048 576 + 524 288 + 131 072 + 65 536 + 8 192 + 4 096 + 2 048 + 1 024 + 512 + 256 + 128 + 64 + 32 + 16 + 4 + 1)(10) =
4 971 974 168 401 362 933(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0100 0101 0000 0000 0000 0000 0010 1001 1101 1011 1111 1011 0011 1111 1111 0101(2) = 4 971 974 168 401 362 933(10)
The number 0100 0101 0000 0000 0000 0000 0010 1001 1101 1011 1111 1011 0011 1111 1111 0101(2), signed binary in one's (1's) complement representation, converted and written as an integer in decimal system (base ten):
0100 0101 0000 0000 0000 0000 0010 1001 1101 1011 1111 1011 0011 1111 1111 0101(2) = 4 971 974 168 401 362 933(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.