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Signed number representations

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values when they were transmitted from a register to the math unit and then converted back to sign–magnitude when the result was transmitted back to the register. The electronics required more gates than the other systems – a key concern when the cost and packaging of discrete transistors were critical. IBM was one of the early supporters of sign–magnitude, with their
246:(−0). Negative zero behaves exactly like positive zero: when used as an operand in any calculation, the result will be the same whether an operand is positive or negative zero. The disadvantage is that the existence of two forms of the same value necessitates two comparisons when checking for equality with zero. Ones' complement subtraction can also result in an 222:, the system that is dominant today. Another camp supported ones' complement, where a negative value is formed by inverting all of the bits in its positive equivalent. A third group supported sign–magnitude, where a value is changed from positive to negative simply by toggling the word's highest-order bit. 277:
Two's complement is the easiest to implement in hardware, which may be the ultimate reason for its widespread popularity. Processors on the early mainframes often consisted of thousands of transistors, so eliminating a significant number of transistors was a significant cost savings. Mainframes such
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is almost a sign bit; zero has the same least significant bit (0) as all the negative numbers. This choice results in the largest magnitude representable positive number being one higher than the largest magnitude negative number, unlike in two's complement or the Protocol Buffers zig-zag encoding.
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There were arguments for and against each of the systems. Sign–magnitude allowed for easier tracing of memory dumps (a common process in the 1960s) as small numeric values use fewer 1 bits. These systems did ones' complement math internally, so numbers would have to be converted to ones' complement
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The early days of digital computing were marked by competing ideas about both hardware technology and mathematics technology (numbering systems). One of the great debates was the format of negative numbers, with some of the era's top experts expressing very strong and differing opinions. One camp
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The range of numbers that can be represented is asymmetric. If the word has an even number of bits, the magnitude of the largest negative number that can be represented is twice as large as the largest positive number that can be represented, and vice versa if the word has an odd number of bits.
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of the ones' complement representation. This can also be thought of as the most significant bit representing the inverse of its value in an unsigned integer; in an 8-bit unsigned byte, the most significant bit represents the 128ths place, where in two's complement that bit would represent −128.
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lowest significant bits of a product (value of multiplication). For instance, a two's-complement addition of 127 and −128 gives the same binary bit pattern as an unsigned addition of 127 and 128, as can be seen from the 8-bit two's complement table.
250:(described below). It can be argued that this makes the addition and subtraction logic more complicated or that it makes it simpler, as a subtraction requires simply inverting the bits of the second operand as it is passed to the adder. The 241:
Ones' complement allowed for somewhat simpler hardware designs, as there was no need to convert values when passed to and from the math unit. But it also shared an undesirable characteristic with sign–magnitude: the ability to represent
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Addition and subtraction require different behavior depending on the sign bit, whereas ones' complement can ignore the sign bit and just do an end-around carry, and two's complement can ignore the sign bit and depend on the overflow
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In two's-complement, there is only one zero, represented as 00000000. Negating a number (whether negative or positive) is done by inverting all the bits and then adding one to that result. This actually reflects the
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binary decimal 11111110 −1 + 00000010 +2 ─────────── ── 1 00000000 0 ← Not the correct answer 1 +1 ← Add carry ─────────── ── 00000001 1 ← Correct answer
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There is no definitive criterion by which any of the representations is universally superior. For integers, the representation used in most current computing devices is two's complement, although the
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the magnitude (inverting all the bits after the first). For example, the decimal number −125 with its sign–magnitude representation 11111101 can be represented in ones' complement form as 10000010.
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Comparison also requires inspecting the sign bit, whereas in two's complement, one can simply subtract the two numbers, and check if the outcome is positive or negative.
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is represented by an all-zero bit pattern. This can be seen as a slight modification and generalization of the aforementioned two's-complement, which is virtually the
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In the previous example, the first binary addition gives 00000000, which is incorrect. The correct result (00000001) only appears when the carry is added back in.
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This approach is directly comparable to the common way of showing a sign (placing a "+" or "−" next to the number's magnitude). Some early binary computers (e.g.,
53: 788:(i.e. the "complement") of the positive number. Like sign–magnitude representation, ones' complement has two representations of 0: 00000000 (+0) and 11111111 ( 834:
back into the resulting sum. To see why this is necessary, consider the following example showing the case of the addition of −1 (11111110) to +2 (00000010):
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from the ones' complement representation of zero that is a long sequence of ones (−0). Two's complement arithmetic, on the other hand, forms the negation of
314:, etc.) also chose to use two's complement math. As IC technology advanced, two's complement technology was adopted in virtually all processors, including 2886: 597:) use this representation, perhaps because of its natural relation to common usage. Sign–magnitude is the most common way of representing the 100: 72: 1529:
representation, a signed number is represented using a number system with base −2. In conventional binary number systems, the base, or
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Note that the ones' complement representation of a negative number can be obtained from the sign–magnitude representation merely by
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and so on, with alternating sign. The numbers that can be represented with four bits are shown in the comparison table below.
57: 547:, only seven bits represent the magnitude, which can range from 0000000 (0) to 1111111 (127). Thus numbers ranging from −127 826:
To add two numbers represented in this system, one does a conventional binary addition, but it is then necessary to do an
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to +0. Therefore, ones' complement and two's complement representations of the same negative value will differ by one.
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Same table, as viewed from "given these binary bits, what is the number as interpreted by the representation system":
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0101011. Using sign–magnitude representation has multiple consequences which makes them more intricate to implement:
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Shedletsky, John J. (1977). "Comment on the Sequential and Indeterminate Behavior of an End-Around-Carry Adder".
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Invert all the bits through the number. This computes the same result as subtracting from negative one.
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The following table shows the positive and negative integers that can be represented using four bits.
539:, set to 0 for a positive number and to 1 for a negative number), and the magnitude of the number (or 158:, negative numbers in any base are represented by prefixing them with a minus sign ("−"). However, in 3025: 2768: 2720: 1367: 536: 531:, a signed number is represented by the bit pattern corresponding to the sign of the number for the 892: 873: 614: 219: 199: 2667:
encoding intended for nonnegative (unsigned) integers to be used efficiently for signed integers.
3005: 2967: 2822: 1058: 1054: 880: 163: 3047: 2757:"Two's complement computation sharing multiplier and its applications to high performance DFE" 1335:, a signed number is represented by the bit pattern corresponding to the unsigned number plus 327: 247: 3001: 2706:
also expressed preference for such modified decimal numbers to reduce errors in computation.
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representation, a negative number is represented by the bit pattern corresponding to the
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representation, a negative number is represented by the bit pattern corresponding to the
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advocated reducing expressions to "small numbers", numerals 1, 2, 3, 4, and 5. In 1840,
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The minimum negative number is −127, instead of −128 as in the case of two's complement.
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A remark on terminology: The system is referred to as "ones' complement" because the
283: 243: 175: 2971: 2915:, "Array multiplier operating in one's complement format", issued 1981-03-10 1122:
An easier method to get the negation of a number in two's complement is as follows:
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can be represented once the sign bit (the eighth bit) is added. For example, −43
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to represent the sign and has a single representation of zero. This allows a
2963: 2862: 2780: 347: 323: 140: 1402: 1378: 845: 594: 532: 259: 235: 2659:"zig-zag encoding" is a system similar to sign–magnitude, but uses the 1364: 343: 339: 231: 227: 2934:, "One's complement cryptographic combiner", issued 1999-12-11 789: 576: 170:, without extra symbols. The four best-known methods of extending the 1185:
Example: for +2, which is 00000010 in binary (the ~ character is the
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machines. The architects of the early integrated-circuit-based CPUs (
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Biased representations are now primarily used for the exponent of
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There are two ways to represent zero, 00000000 (0) and 10000000 (
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series computers being perhaps the best-known systems to use it.
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Intel 64 and IA-32 Architectures Software Developer's Manual
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As an example, the ones' complement form of 00101011 (43
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with zero being either 00000000 (+0) or 11111111 (−0).
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use two's complement, as did minicomputers such as the
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Choo, Hunsoo; Muhammad, K.; Roy, K. (February 2003).
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Encoding of negative numbers in binary number systems
1192:operator, so ~X means "invert all the bits in X"): 60:. Unsourced material may be challenged and removed. 1156:2. Invert all of the bits to the left of that "1" 1098: 2990:, Volume 2: Seminumerical Algorithms, chapter 4.1 807:numbers using ones' complement is represented by 1199:11111101 + 1 → 11111110 (−2 in two's complement) 1138:1. Starting from the right, find the first "1" 166:, numbers are represented only as sequences of 1099:{\displaystyle \mathbb {Z} /2^{N}\mathbb {Z} } 274:computer use ones' complement representation. 815:and ±0. A conventional eight-bit byte is −127 8: 2682:to negative numbers. In that extension, the 198:. Corresponding methods can be devised for 2796:GE-625 / 635 Programming Reference Manual 1974: 1971: 1968: 1959: 1092: 1091: 1085: 1076: 1072: 1071: 1069: 872:from a single large power of two that is 187: 183: 120:Learn how and when to remove this message 2250: 1559: 1418: 1213: 1124: 896: 618: 357: 2747: 2761:IEEE Transactions on Signal Processing 1393:(64-bit) exponent field is an 11-bit 7: 2887:"Computer Science 315 Lecture Notes" 860:) can also be formed by subtracting 58:adding citations to reliable sources 179: 2676:High Efficiency Video Coding/H.265 25: 3026:Protocol Buffers: Signed Integers 2690:Another approach is to give each 1561:Four-bit integer representations 209:mainframes use ones' complement. 3037:The Logic of Computer Arithmetic 2680:extend exponential-Golomb coding 2670:A similar method is used in the 1381:defines the exponent field of a 1379:IEEE 754 floating-point standard 906:Two's complement interpretation 628:Ones' complement interpretation 559:encoded in an eight-bit byte is 34: 2987:The Art of Computer Programming 2678:video compression standards to 69:"Signed number representations" 45:needs additional citations for 3044:Computer Arithmetic Algorithms 2952:IEEE Transactions on Computers 367:Sign–magnitude interpretation 207:Unisys ClearPath Dorado series 1: 2885:Bacon, Jason W. (2010–2011). 830:: that is, add any resulting 191: 145:signed number representations 3000:Thomas Finley (April 2000). 2224:−11     2201:−10     1385:(32-bit) number as an 8-bit 1324:representation, also called 1164: 1158: 1146: 1140: 523:representation, also called 195: 2696:signed-digit representation 2672:Advanced Video Coding/H.264 2223: 2200: 2178:−9     2177: 2155:−8     2154: 2132:−7     2131: 2109:−6     2108: 2086:−5     2085: 2063:−4     2062: 2040:−3     2039: 2017:−2     2016: 1994:−1     1993: 1979: 1956: 1933: 1910: 1887: 1864: 1841: 1818: 1795: 1772: 1749: 1727:10     1726: 1704:11     1703: 1681:12     1680: 1658:13     1657: 1635:14     1634: 1612:15     1611: 1589:16     1588: 1351:. Thus 0 is represented by 898:Eight-bit two's complement 620:Eight-bit ones' complement 134:Signed-digit representation 3083: 1957:0     1934:1     1911:2     1888:3     1865:4     1842:5     1819:6     1796:7     1773:8     1750:9     1537:, the next bit represents 1412: 1223:Excess-128 interpretation 1207: 1057:structure on all integers 890: 886: 612: 151:in binary number systems. 131: 2698:. For instance, in 1726, 1983:     1110:(except for detection of 608: 359:Eight-bit sign–magnitude 2665:variable-length quantity 1431:Unsigned interpretation 1226:Unsigned interpretation 909:Unsigned interpretation 631:Unsigned interpretation 370:Unsigned interpretation 132:Not to be confused with 2964:10.1109/TC.1977.1674817 2781:10.1109/TSP.2002.806984 1428:Base −2 interpretation 799:) becomes 11010100 (−43 147:are required to encode 3046:, A.K. Peters (2002), 3039:, Prentice-Hall (1963) 2855:Power ISA Version 2.07 2726:Computer number format 1100: 2731:Method of complements 2694:a sign, yielding the 2684:least significant bit 2661:least significant bit 1215:Eight-bit excess-128 1101: 881:bitwise complementing 172:binary numeral system 2721:Binary-coded decimal 1368:most significant bit 1363:representation with 1196:~00000010 → 11111101 1068: 852:(represented as the 848:of a positive value 537:most significant bit 54:improve this article 3067:Computer arithmetic 2893:on 14 February 2020 2773:2003ITSP...51..458C 1562: 1421: 1216: 899: 621: 360: 3006:Cornell University 3002:"Two's Complement" 1581:Excess-8 (biased) 1560: 1420:Eight-bit base −2 1419: 1214: 1096: 897: 619: 525:sign-and-magnitude 358: 2648: 2647: 2246: 2245: 1578:Two's complement 1575:Ones' complement 1523: 1522: 1318: 1317: 1172: 1171: 1034: 1033: 778: 777: 517: 516: 248:end-around borrow 130: 129: 122: 104: 16:(Redirected from 3074: 3028: 3023: 3017: 3016: 3014: 3012: 2997: 2991: 2982: 2976: 2975: 2947: 2941: 2940: 2939: 2935: 2928: 2922: 2921: 2920: 2916: 2909: 2903: 2902: 2900: 2898: 2889:. Archived from 2882: 2876: 2874: 2872: 2870: 2860: 2850: 2844: 2843: 2841: 2839: 2829: 2819: 2813: 2812: 2810: 2808: 2801:General Electric 2791: 2785: 2784: 2752: 2716:Balanced ternary 2657:Protocol Buffers 2266:Two's complement 2263:Ones' complement 2251: 1563: 1553:Comparison table 1544: 1540: 1536: 1422: 1391:double-precision 1383:single-precision 1362: 1217: 1125: 1108:unsigned numbers 1105: 1103: 1102: 1097: 1095: 1090: 1089: 1080: 1075: 1046:end-around carry 1038:two's complement 900: 893:Two's complement 887:Two's complement 828:end-around carry 814: 810: 803:). The range of 782:ones' complement 622: 615:Ones' complement 609:Ones' complement 563:0101011 while 43 529:signed magnitude 361: 220:two's complement 188:two's complement 184:ones' complement 149:negative numbers 125: 118: 114: 111: 105: 103: 62: 38: 30: 21: 18:End-around carry 3082: 3081: 3077: 3076: 3075: 3073: 3072: 3071: 3057: 3056: 3032: 3031: 3024: 3020: 3010: 3008: 2999: 2998: 2994: 2983: 2979: 2949: 2948: 2944: 2937: 2930: 2929: 2925: 2918: 2911: 2910: 2906: 2896: 2894: 2884: 2883: 2879: 2868: 2866: 2858: 2852: 2851: 2847: 2837: 2835: 2834:. Section 4.2.1 2827: 2821: 2820: 2816: 2806: 2804: 2793: 2792: 2788: 2754: 2753: 2749: 2744: 2712: 2704:Augustin Cauchy 2653: 1572:Sign–magnitude 1555: 1542: 1541:, the next bit 1538: 1534: 1417: 1411: 1360: 1358: 1354: 1342: 1338: 1329: 1212: 1206: 1081: 1066: 1065: 895: 889: 871: 868:by subtracting 867: 863: 859: 851: 839: 822: 818: 812: 808: 802: 798: 617: 611: 566: 558: 554: 550: 356: 264:CDC 6000 series 215: 137: 126: 115: 109: 106: 63: 61: 51: 39: 28: 23: 22: 15: 12: 11: 5: 3080: 3078: 3070: 3069: 3059: 3058: 3055: 3054: 3042:Israel Koren, 3040: 3030: 3029: 3018: 2992: 2984:Donald Knuth: 2977: 2958:(3): 271–272. 2942: 2923: 2904: 2877: 2845: 2814: 2803:. January 1966 2786: 2767:(2): 458–469. 2746: 2745: 2743: 2740: 2739: 2738: 2733: 2728: 2723: 2718: 2711: 2708: 2652: 2649: 2646: 2645: 2642: 2639: 2636: 2631: 2628: 2625: 2621: 2620: 2617: 2614: 2611: 2608: 2605: 2602: 2598: 2597: 2594: 2591: 2588: 2585: 2582: 2579: 2575: 2574: 2571: 2568: 2565: 2562: 2559: 2556: 2552: 2551: 2548: 2545: 2542: 2539: 2536: 2533: 2529: 2528: 2525: 2522: 2519: 2516: 2513: 2510: 2506: 2505: 2502: 2499: 2496: 2493: 2490: 2487: 2483: 2482: 2479: 2476: 2473: 2470: 2465: 2462: 2458: 2457: 2454: 2451: 2448: 2445: 2442: 2439: 2435: 2434: 2431: 2428: 2425: 2422: 2419: 2416: 2412: 2411: 2408: 2405: 2402: 2399: 2396: 2393: 2389: 2388: 2385: 2382: 2379: 2376: 2373: 2370: 2366: 2365: 2362: 2359: 2356: 2353: 2350: 2347: 2343: 2342: 2339: 2336: 2333: 2330: 2327: 2324: 2320: 2319: 2316: 2313: 2310: 2307: 2304: 2301: 2297: 2296: 2293: 2290: 2287: 2284: 2281: 2278: 2274: 2273: 2270: 2267: 2264: 2261: 2260:Sign–magnitude 2258: 2255: 2244: 2243: 2240: 2237: 2234: 2231: 2228: 2225: 2221: 2220: 2217: 2214: 2211: 2208: 2205: 2202: 2198: 2197: 2194: 2191: 2188: 2185: 2182: 2179: 2175: 2174: 2171: 2168: 2165: 2162: 2159: 2156: 2152: 2151: 2148: 2145: 2142: 2139: 2136: 2133: 2129: 2128: 2125: 2122: 2119: 2116: 2113: 2110: 2106: 2105: 2102: 2099: 2096: 2093: 2090: 2087: 2083: 2082: 2079: 2076: 2073: 2070: 2067: 2064: 2060: 2059: 2056: 2053: 2050: 2047: 2044: 2041: 2037: 2036: 2033: 2030: 2027: 2024: 2021: 2018: 2014: 2013: 2010: 2007: 2004: 2001: 1998: 1995: 1991: 1990: 1987: 1984: 1977: 1976: 1973: 1970: 1967: 1964: 1961: 1958: 1954: 1953: 1950: 1947: 1944: 1941: 1938: 1935: 1931: 1930: 1927: 1924: 1921: 1918: 1915: 1912: 1908: 1907: 1904: 1901: 1898: 1895: 1892: 1889: 1885: 1884: 1881: 1878: 1875: 1872: 1869: 1866: 1862: 1861: 1858: 1855: 1852: 1849: 1846: 1843: 1839: 1838: 1835: 1832: 1829: 1826: 1823: 1820: 1816: 1815: 1812: 1809: 1806: 1803: 1800: 1797: 1793: 1792: 1789: 1786: 1783: 1780: 1777: 1774: 1770: 1769: 1766: 1763: 1760: 1757: 1754: 1751: 1747: 1746: 1743: 1740: 1737: 1734: 1731: 1728: 1724: 1723: 1720: 1717: 1714: 1711: 1708: 1705: 1701: 1700: 1697: 1694: 1691: 1688: 1685: 1682: 1678: 1677: 1674: 1671: 1668: 1665: 1662: 1659: 1655: 1654: 1651: 1648: 1645: 1642: 1639: 1636: 1632: 1631: 1628: 1625: 1622: 1619: 1616: 1613: 1609: 1608: 1605: 1602: 1599: 1596: 1593: 1590: 1586: 1585: 1582: 1579: 1576: 1573: 1570: 1567: 1554: 1551: 1521: 1520: 1517: 1514: 1510: 1509: 1506: 1503: 1499: 1498: 1495: 1492: 1488: 1487: 1484: 1481: 1477: 1476: 1473: 1470: 1466: 1465: 1462: 1459: 1455: 1454: 1451: 1448: 1444: 1443: 1440: 1437: 1433: 1432: 1429: 1426: 1410: 1407: 1375:floating-point 1356: 1352: 1340: 1336: 1327: 1316: 1315: 1312: 1309: 1305: 1304: 1301: 1298: 1294: 1293: 1290: 1287: 1283: 1282: 1279: 1276: 1272: 1271: 1268: 1265: 1261: 1260: 1257: 1254: 1250: 1249: 1246: 1243: 1239: 1238: 1235: 1232: 1228: 1227: 1224: 1221: 1208:Main article: 1205: 1202: 1201: 1200: 1197: 1183: 1182: 1179: 1170: 1169: 1163: 1157: 1153: 1152: 1145: 1139: 1135: 1134: 1131: 1128: 1094: 1088: 1084: 1079: 1074: 1032: 1031: 1028: 1025: 1021: 1020: 1017: 1014: 1010: 1009: 1006: 1003: 999: 998: 995: 992: 988: 987: 984: 981: 977: 976: 973: 970: 966: 965: 962: 959: 955: 954: 951: 948: 944: 943: 940: 937: 933: 932: 929: 926: 922: 921: 918: 915: 911: 910: 907: 904: 891:Main article: 888: 885: 869: 865: 861: 857: 849: 836: 820: 816: 800: 796: 776: 775: 772: 769: 765: 764: 761: 758: 754: 753: 750: 747: 743: 742: 739: 736: 732: 731: 728: 725: 721: 720: 717: 714: 710: 709: 706: 703: 699: 698: 695: 692: 688: 687: 684: 681: 677: 676: 673: 670: 666: 665: 662: 659: 655: 654: 651: 648: 644: 643: 640: 637: 633: 632: 629: 626: 613:Main article: 610: 607: 603:floating-point 591: 590: 587: 584: 580: 564: 556: 552: 548: 541:absolute value 521:sign–magnitude 515: 514: 511: 508: 504: 503: 500: 497: 493: 492: 489: 486: 482: 481: 478: 475: 471: 470: 467: 464: 460: 459: 456: 453: 449: 448: 445: 442: 438: 437: 434: 431: 427: 426: 423: 420: 416: 415: 412: 409: 405: 404: 401: 398: 394: 393: 390: 387: 383: 382: 379: 376: 372: 371: 368: 365: 355: 354:Sign–magnitude 352: 280:IBM System/360 256:CDC 160 series 214: 211: 180:sign–magnitude 176:signed numbers 128: 127: 42: 40: 33: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 3079: 3068: 3065: 3064: 3062: 3053: 3052:1-56881-160-8 3049: 3045: 3041: 3038: 3035:Ivan Flores, 3034: 3033: 3027: 3022: 3019: 3007: 3003: 2996: 2993: 2989: 2988: 2981: 2978: 2973: 2969: 2965: 2961: 2957: 2953: 2946: 2943: 2933: 2927: 2924: 2914: 2908: 2905: 2892: 2888: 2881: 2878: 2865:. Section 1.4 2864: 2857: 2856: 2849: 2846: 2833: 2826: 2825: 2818: 2815: 2802: 2798: 2797: 2790: 2787: 2782: 2778: 2774: 2770: 2766: 2762: 2758: 2751: 2748: 2741: 2737: 2734: 2732: 2729: 2727: 2724: 2722: 2719: 2717: 2714: 2713: 2709: 2707: 2705: 2701: 2697: 2693: 2688: 2685: 2681: 2677: 2673: 2668: 2666: 2662: 2658: 2651:Other systems 2650: 2643: 2640: 2637: 2635: 2632: 2629: 2626: 2623: 2622: 2618: 2615: 2612: 2609: 2606: 2603: 2600: 2599: 2595: 2592: 2589: 2586: 2583: 2580: 2577: 2576: 2572: 2569: 2566: 2563: 2560: 2557: 2554: 2553: 2549: 2546: 2543: 2540: 2537: 2534: 2531: 2530: 2526: 2523: 2520: 2517: 2514: 2511: 2508: 2507: 2503: 2500: 2497: 2494: 2491: 2488: 2485: 2484: 2480: 2477: 2474: 2471: 2469: 2466: 2463: 2460: 2459: 2455: 2452: 2449: 2446: 2443: 2440: 2437: 2436: 2432: 2429: 2426: 2423: 2420: 2417: 2414: 2413: 2409: 2406: 2403: 2400: 2397: 2394: 2391: 2390: 2386: 2383: 2380: 2377: 2374: 2371: 2368: 2367: 2363: 2360: 2357: 2354: 2351: 2348: 2345: 2344: 2340: 2337: 2334: 2331: 2328: 2325: 2322: 2321: 2317: 2314: 2311: 2308: 2305: 2302: 2299: 2298: 2294: 2291: 2288: 2285: 2282: 2279: 2276: 2275: 2271: 2268: 2265: 2262: 2259: 2256: 2253: 2252: 2249: 2241: 2238: 2235: 2232: 2229: 2226: 2222: 2218: 2215: 2212: 2209: 2206: 2203: 2199: 2195: 2192: 2189: 2186: 2183: 2180: 2176: 2172: 2169: 2166: 2163: 2160: 2157: 2153: 2149: 2146: 2143: 2140: 2137: 2134: 2130: 2126: 2123: 2120: 2117: 2114: 2111: 2107: 2103: 2100: 2097: 2094: 2091: 2088: 2084: 2080: 2077: 2074: 2071: 2068: 2065: 2061: 2057: 2054: 2051: 2048: 2045: 2042: 2038: 2034: 2031: 2028: 2025: 2022: 2019: 2015: 2011: 2008: 2005: 2002: 1999: 1996: 1992: 1988: 1985: 1982: 1978: 1965: 1962: 1955: 1951: 1948: 1945: 1942: 1939: 1936: 1932: 1928: 1925: 1922: 1919: 1916: 1913: 1909: 1905: 1902: 1899: 1896: 1893: 1890: 1886: 1882: 1879: 1876: 1873: 1870: 1867: 1863: 1859: 1856: 1853: 1850: 1847: 1844: 1840: 1836: 1833: 1830: 1827: 1824: 1821: 1817: 1813: 1810: 1807: 1804: 1801: 1798: 1794: 1790: 1787: 1784: 1781: 1778: 1775: 1771: 1767: 1764: 1761: 1758: 1755: 1752: 1748: 1744: 1741: 1738: 1735: 1732: 1729: 1725: 1721: 1718: 1715: 1712: 1709: 1706: 1702: 1698: 1695: 1692: 1689: 1686: 1683: 1679: 1675: 1672: 1669: 1666: 1663: 1660: 1656: 1652: 1649: 1646: 1643: 1640: 1637: 1633: 1629: 1626: 1623: 1620: 1617: 1614: 1610: 1606: 1603: 1600: 1597: 1594: 1591: 1587: 1583: 1580: 1577: 1574: 1571: 1568: 1565: 1564: 1558: 1552: 1550: 1546: 1532: 1528: 1518: 1515: 1512: 1511: 1507: 1504: 1501: 1500: 1496: 1493: 1490: 1489: 1485: 1482: 1479: 1478: 1474: 1471: 1468: 1467: 1463: 1460: 1457: 1456: 1452: 1449: 1446: 1445: 1441: 1438: 1435: 1434: 1430: 1427: 1425:Binary value 1424: 1423: 1416: 1415:Negative base 1408: 1406: 1404: 1400: 1399:exponent bias 1396: 1392: 1388: 1384: 1380: 1377:numbers. The 1376: 1371: 1369: 1366: 1350: 1346: 1345:biasing value 1334: 1330: 1323: 1322:offset binary 1313: 1310: 1307: 1306: 1302: 1299: 1296: 1295: 1291: 1288: 1285: 1284: 1280: 1277: 1274: 1273: 1269: 1266: 1263: 1262: 1258: 1255: 1252: 1251: 1247: 1244: 1241: 1240: 1236: 1233: 1230: 1229: 1225: 1222: 1220:Binary value 1219: 1218: 1211: 1210:Offset binary 1204:Offset binary 1203: 1198: 1195: 1194: 1193: 1191: 1188: 1180: 1177: 1176: 1175: 1167: 1161: 1155: 1154: 1150: 1144: 1137: 1136: 1132: 1129: 1127: 1126: 1123: 1120: 1117: 1113: 1109: 1086: 1082: 1077: 1063: 1060: 1056: 1050: 1047: 1043: 1039: 1029: 1026: 1023: 1022: 1018: 1015: 1012: 1011: 1007: 1004: 1001: 1000: 996: 993: 990: 989: 985: 982: 979: 978: 974: 971: 968: 967: 963: 960: 957: 956: 952: 949: 946: 945: 941: 938: 935: 934: 930: 927: 924: 923: 919: 916: 913: 912: 908: 905: 903:Binary value 902: 901: 894: 884: 882: 877: 875: 855: 847: 842: 835: 833: 829: 824: 806: 793: 791: 787: 783: 773: 770: 767: 766: 762: 759: 756: 755: 751: 748: 745: 744: 740: 737: 734: 733: 729: 726: 723: 722: 718: 715: 712: 711: 707: 704: 701: 700: 696: 693: 690: 689: 685: 682: 679: 678: 674: 671: 668: 667: 663: 660: 657: 656: 652: 649: 646: 645: 641: 638: 635: 634: 630: 627: 625:Binary value 624: 623: 616: 606: 604: 600: 596: 588: 585: 581: 578: 574: 573: 572: 570: 562: 546: 542: 538: 534: 530: 526: 522: 512: 509: 506: 505: 501: 498: 495: 494: 490: 487: 484: 483: 479: 476: 473: 472: 468: 465: 462: 461: 457: 454: 451: 450: 446: 443: 440: 439: 435: 432: 429: 428: 424: 421: 418: 417: 413: 410: 407: 406: 402: 399: 396: 395: 391: 388: 385: 384: 380: 377: 374: 373: 369: 366: 364:Binary value 363: 362: 353: 351: 349: 345: 341: 337: 333: 329: 325: 321: 317: 313: 309: 305: 301: 297: 293: 289: 285: 284:GE-600 series 281: 275: 273: 269: 265: 261: 257: 253: 249: 245: 244:negative zero 239: 237: 233: 229: 223: 221: 212: 210: 208: 203: 201: 197: 193: 192:offset binary 189: 185: 181: 177: 174:to represent 173: 169: 165: 161: 157: 152: 150: 146: 142: 135: 124: 121: 113: 102: 99: 95: 92: 88: 85: 81: 78: 74: 71: –  70: 66: 65:Find sources: 59: 55: 49: 48: 43:This article 41: 37: 32: 31: 19: 3043: 3036: 3021: 3011:15 September 3009:. Retrieved 2995: 2985: 2980: 2955: 2951: 2945: 2926: 2907: 2895:. Retrieved 2891:the original 2880: 2867:. Retrieved 2854: 2848: 2836:. Retrieved 2823: 2817: 2805:. Retrieved 2795: 2789: 2764: 2760: 2750: 2689: 2669: 2654: 2247: 1556: 1547: 1526: 1524: 1372: 1348: 1344: 1332: 1325: 1321: 1319: 1184: 1174:Method two: 1173: 1165: 1159: 1148: 1142: 1121: 1115: 1051: 1037: 1035: 878: 843: 840: 827: 825: 794: 781: 779: 592: 568: 560: 528: 524: 520: 518: 276: 270:series, and 240: 224: 216: 204: 153: 144: 138: 116: 107: 97: 90: 83: 76: 64: 52:Please help 47:verification 44: 2897:21 February 2869:November 2, 2700:John Colson 1397:field; see 1395:excess-1023 1389:field. The 1190:bitwise NOT 1042:bitwise NOT 854:bitwise NOT 786:bitwise NOT 599:significand 535:(often the 268:UNIVAC 1100 200:other bases 156:mathematics 2932:US 6760440 2913:US 4484301 2807:August 15, 2742:References 2736:Signedness 1413:See also: 1387:excess-127 1361:excess-(2) 1343:being the 1133:Example 2 1130:Example 1 312:Intel 8080 286:, and the 218:supported 110:April 2013 80:newspapers 2863:Power.org 2838:August 6, 2655:Google's 1569:Unsigned 1543:(−2) = +4 1539:(−2) = −2 1535:(−2) = +1 874:congruent 583:behavior. 348:DEC Alpha 324:Power ISA 164:registers 141:computing 3061:Category 2972:14661474 2710:See also 2272:Base −2 2269:Excess-8 2257:Unsigned 1584:Base −2 1566:Decimal 1513:11111111 1491:10000001 1480:10000000 1469:01111111 1447:00000001 1436:00000000 1403:excess-3 1308:11111111 1286:10000001 1275:10000000 1264:01111111 1242:00000001 1231:00000000 1112:overflow 1024:11111111 1013:11111110 991:10000010 980:10000001 969:10000000 958:01111111 947:01111110 925:00000001 914:00000000 846:negation 809:−(2 − 1) 768:11111111 757:11111110 746:11111101 724:10000010 713:10000001 702:10000000 691:01111111 680:01111110 669:01111101 647:00000001 636:00000000 605:values. 595:IBM 7090 533:sign bit 507:11111111 496:11111110 485:11111101 463:10000010 452:10000001 441:10000000 430:01111111 419:01111110 408:01111101 386:00000001 375:00000000 302:and the 262:series, 260:CDC 3000 2769:Bibcode 1527:base −2 1525:In the 1409:Base −2 1365:negated 1355:, and − 1339:, with 1326:excess- 1320:In the 1181:Add one 1160:1101011 1141:0010100 1036:In the 819:to +127 813:(2 − 1) 780:In the 551:to +127 519:In the 344:PA-RISC 340:Itanium 278:as the 213:History 196:base −2 162:or CPU 94:scholar 3050:  2970:  2938:  2919:  2254:Binary 1349:offset 1333:biased 1059:modulo 805:signed 346:, and 304:PDP-11 292:PDP-10 282:, the 190:, and 96:  89:  82:  75:  67:  2968:S2CID 2859:(PDF) 2832:Intel 2828:(PDF) 2692:digit 2219:1010 2196:1011 2173:1000 2170:0000 2167:1000 2150:1001 2147:0001 2144:1001 2141:1000 2138:1111 2127:1110 2124:0010 2121:1010 2118:1001 2115:1110 2104:1111 2101:0011 2098:1011 2095:1010 2092:1101 2081:1100 2078:0100 2075:1100 2072:1011 2069:1100 2058:1101 2055:0101 2052:1101 2049:1100 2046:1011 2035:0010 2032:0110 2029:1110 2026:1101 2023:1010 2012:0011 2009:0111 2006:1111 2003:1110 2000:1001 1989:1111 1986:1000 1975:0000 1972:1000 1969:0000 1966:0000 1963:0000 1960:0000 1952:0001 1949:1001 1946:0001 1943:0001 1940:0001 1937:0001 1929:0110 1926:1010 1923:0010 1920:0010 1917:0010 1914:0010 1906:0111 1903:1011 1900:0011 1897:0011 1894:0011 1891:0011 1883:0100 1880:1100 1877:0100 1874:0100 1871:0100 1868:0100 1860:0101 1857:1101 1854:0101 1851:0101 1848:0101 1845:0101 1834:1110 1831:0110 1828:0110 1825:0110 1822:0110 1811:1111 1808:0111 1805:0111 1802:0111 1799:0111 1776:1000 1753:1001 1730:1010 1707:1011 1684:1100 1661:1101 1638:1110 1615:1111 1531:radix 1166:11010 1147:00101 832:carry 332:SPARC 300:PDP-8 296:PDP-5 288:PDP-6 252:PDP-1 178:are: 101:JSTOR 87:books 3048:ISBN 3013:2015 2899:2020 2871:2023 2840:2013 2809:2013 2674:and 2624:1111 2601:1110 2578:1101 2555:1100 2532:1011 2527:−10 2509:1010 2486:1001 2461:1000 2438:0111 2415:0110 2392:0101 2369:0100 2346:0011 2323:0010 2300:0001 2277:0000 1519:255 1497:129 1494:−127 1486:128 1483:−128 1475:127 1314:255 1292:129 1281:128 1270:127 1245:−127 1234:−128 1168:100 1055:ring 1030:255 1019:254 997:130 994:−126 986:129 983:−127 975:128 972:−128 964:127 953:126 774:255 763:254 752:253 730:130 727:−125 719:129 716:−126 708:128 705:−127 697:127 686:126 675:125 545:byte 513:255 510:−127 502:254 499:−126 491:253 488:−125 469:130 458:129 447:128 436:127 425:126 414:125 328:MIPS 320:m68k 306:and 298:and 290:and 272:LINC 236:709x 234:and 168:bits 73:news 2960:doi 2777:doi 2644:−5 2619:−6 2596:−3 2573:−4 2550:−9 2504:−7 2481:−8 2364:−1 2341:−2 1516:−85 1347:or 1331:or 1311:127 1151:00 961:127 950:126 856:of 811:to 792:). 694:127 683:126 672:125 601:in 567:is 527:or 433:127 422:126 411:125 336:ARM 316:x86 308:VAX 232:709 228:704 160:RAM 154:In 139:In 56:by 3063:: 3004:. 2966:. 2956:26 2954:. 2861:. 2830:. 2799:. 2775:. 2765:51 2763:. 2759:. 2638:−1 2634:−0 2630:−7 2627:15 2613:−2 2610:−1 2607:−6 2604:14 2590:−3 2587:−2 2584:−5 2581:13 2567:−4 2564:−3 2561:−4 2558:12 2544:−5 2541:−4 2538:−3 2535:11 2521:−6 2518:−5 2515:−2 2512:10 2498:−7 2495:−6 2492:−1 2475:−8 2472:−7 2468:−0 2456:3 2453:−1 2433:2 2430:−2 2410:5 2407:−3 2387:4 2384:−4 2361:−5 2338:−6 2318:1 2315:−7 2295:0 2292:−8 2242:— 2239:— 2236:— 2233:— 2230:— 2227:— 2216:— 2213:— 2210:— 2207:— 2204:— 2193:— 2190:— 2187:— 2184:— 2181:— 2164:— 2161:— 2158:— 2135:— 2112:— 2089:— 2066:— 2043:— 2020:— 1997:— 1981:−0 1837:— 1814:— 1791:— 1788:— 1785:— 1782:— 1779:— 1768:— 1765:— 1762:— 1759:— 1756:— 1745:— 1742:— 1739:— 1736:— 1733:— 1722:— 1719:— 1716:— 1713:— 1710:— 1699:— 1696:— 1693:— 1690:— 1687:— 1676:— 1673:— 1670:— 1667:— 1664:— 1653:— 1650:— 1647:— 1644:— 1641:— 1630:— 1627:— 1624:— 1621:— 1618:— 1607:— 1604:— 1601:— 1598:— 1595:— 1592:— 1508:⋮ 1472:43 1464:⋮ 1453:1 1442:0 1405:. 1370:. 1303:⋮ 1267:−1 1259:⋮ 1248:1 1237:0 1162:1 1064:: 1027:−1 1016:−2 1008:⋮ 942:⋮ 931:1 920:0 821:10 817:10 801:10 797:10 790:−0 771:−0 760:−1 749:−2 741:⋮ 664:⋮ 653:1 642:0 579:). 577:−0 565:10 557:10 553:10 549:10 480:⋮ 466:−2 455:−1 444:−0 403:⋮ 392:1 381:0 350:. 342:, 338:, 334:, 330:, 326:, 322:, 318:, 266:, 258:, 254:, 230:, 186:, 182:, 143:, 3015:. 2974:. 2962:: 2901:. 2875:, 2873:. 2842:. 2811:. 2783:. 2779:: 2771:: 2641:7 2616:6 2593:5 2570:4 2547:3 2524:2 2501:1 2489:9 2478:0 2464:8 2450:7 2447:7 2444:7 2441:7 2427:6 2424:6 2421:6 2418:6 2404:5 2401:5 2398:5 2395:5 2381:4 2378:4 2375:4 2372:4 2358:3 2355:3 2352:3 2349:3 2335:2 2332:2 2329:2 2326:2 2312:1 2309:1 2306:1 2303:1 2289:0 2286:0 2283:0 2280:0 1505:⋮ 1502:⋮ 1461:⋮ 1458:⋮ 1450:1 1439:0 1357:K 1353:K 1341:K 1337:K 1328:K 1300:⋮ 1297:⋮ 1289:1 1278:0 1256:⋮ 1253:⋮ 1187:C 1149:1 1143:1 1116:N 1093:Z 1087:N 1083:2 1078:/ 1073:Z 1062:2 1005:⋮ 1002:⋮ 939:⋮ 936:⋮ 928:1 917:0 870:x 866:x 862:x 858:x 850:x 738:⋮ 735:⋮ 661:⋮ 658:⋮ 650:1 639:0 569:0 561:1 477:⋮ 474:⋮ 400:⋮ 397:⋮ 389:1 378:0 136:. 123:) 117:( 112:) 108:( 98:· 91:· 84:· 77:· 50:. 20:)

Index

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verification
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"Signed number representations"
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Signed-digit representation
computing
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sign–magnitude
ones' complement
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Unisys ClearPath Dorado series
two's complement
704

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