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?
1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0111 is the binary representation of a negative 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:
!(1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0111) = 0111 1110 0111 1110 0111 1110 0111 1110 0111 1110 0111 1110 0111 1110 0111 1000
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
0 255
0 254
1 253
1 252
1 251
1 250
1 249
1 248
0 247
0 246
1 245
1 244
1 243
1 242
1 241
1 240
0 239
0 238
1 237
1 236
1 235
1 234
1 233
1 232
0 231
0 230
1 229
1 228
1 227
1 226
1 225
1 224
0 223
0 222
1 221
1 220
1 219
1 218
1 217
1 216
0 215
0 214
1 213
1 212
1 211
1 210
1 29
1 28
0 27
0 26
1 25
1 24
1 23
1 22
0 21
0 20
0
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0111 1110 0111 1110 0111 1110 0111 1110 0111 1110 0111 1110 0111 1110 0111 1000(2) =
(0 × 263 + 1 × 262 + 1 × 261 + 1 × 260 + 1 × 259 + 1 × 258 + 1 × 257 + 0 × 256 + 0 × 255 + 1 × 254 + 1 × 253 + 1 × 252 + 1 × 251 + 1 × 250 + 1 × 249 + 0 × 248 + 0 × 247 + 1 × 246 + 1 × 245 + 1 × 244 + 1 × 243 + 1 × 242 + 1 × 241 + 0 × 240 + 0 × 239 + 1 × 238 + 1 × 237 + 1 × 236 + 1 × 235 + 1 × 234 + 1 × 233 + 0 × 232 + 0 × 231 + 1 × 230 + 1 × 229 + 1 × 228 + 1 × 227 + 1 × 226 + 1 × 225 + 0 × 224 + 0 × 223 + 1 × 222 + 1 × 221 + 1 × 220 + 1 × 219 + 1 × 218 + 1 × 217 + 0 × 216 + 0 × 215 + 1 × 214 + 1 × 213 + 1 × 212 + 1 × 211 + 1 × 210 + 1 × 29 + 0 × 28 + 0 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 0 × 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 + 0 + 0 + 18 014 398 509 481 984 + 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 + 0 + 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 + 2 199 023 255 552 + 0 + 0 + 274 877 906 944 + 137 438 953 472 + 68 719 476 736 + 34 359 738 368 + 17 179 869 184 + 8 589 934 592 + 0 + 0 + 1 073 741 824 + 536 870 912 + 268 435 456 + 134 217 728 + 67 108 864 + 33 554 432 + 0 + 0 + 4 194 304 + 2 097 152 + 1 048 576 + 524 288 + 262 144 + 131 072 + 0 + 0 + 16 384 + 8 192 + 4 096 + 2 048 + 1 024 + 512 + 0 + 0 + 64 + 32 + 16 + 8 + 0 + 0 + 0)(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 + 18 014 398 509 481 984 + 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 + 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 + 2 199 023 255 552 + 274 877 906 944 + 137 438 953 472 + 68 719 476 736 + 34 359 738 368 + 17 179 869 184 + 8 589 934 592 + 1 073 741 824 + 536 870 912 + 268 435 456 + 134 217 728 + 67 108 864 + 33 554 432 + 4 194 304 + 2 097 152 + 1 048 576 + 524 288 + 262 144 + 131 072 + 16 384 + 8 192 + 4 096 + 2 048 + 1 024 + 512 + 64 + 32 + 16 + 8)(10) =
9 114 861 777 597 660 792(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0111(2) = -9 114 861 777 597 660 792(10)
The number 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0111(2), signed binary in one's (1's) complement representation, converted and written as an integer in decimal system (base ten):
1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0001 1000 0111(2) = -9 114 861 777 597 660 792(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.