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=~ _ System/3S0
= ::-::. ~ ';' ~ Reference Data
Direct Evaluation of Floating Debugginq
Point Numbers in Hexadecimal Aid




The information in this publication is based in
part on data contained in Form A22.o821-7.




The following tables can be used to evaluate
a floating point number represented in
hexadecimal form. The technique uses a table
lookup in the hexadecimal integer table, and
a table lookup in the hexadecimal fraction
table. The user unites the integer from the
first table with the fraction from the second
table, to form one number, and then performs
a calculation to obtain the value of the
floating point number.
ConWln;on EXlIITJple

Convert the floating point number BFF13A2C to decimal.
1. Look up the three digits to the right of the two characteristic
digits in the direct hexadecimal integer table.

BF~A2C
3859
2. Assume there is a hexadecimal point to the right of the digits
just looked up. Look up the rightmost three digits in the
hexadecimal fraction table, and unite this fraction with the
integer from step 1, above.

BFF 13~
3859.6357
3. Perform a desk calculator operation on the result of step 2,
the operation being determined by the two leftmost hex digits
and the following lists.



Two !Two
leftmost Divide Multiply eftmost Divide Multiply
digits by by ~igits by by

3D ~6,777 ,216 BD -16,777,216
3E 1,048,576 BE -1,048,576
3F 65,536 BF -65,~

40 4,096 CO -4,096
41 256 C1 -256
42 16 C2 -16
43 1 1 C3 -1 -1
44 1E C4 -16
45 25E C5 -256
46 4,09E C6 -4,096
47 65,53E C7 -65,536


3859.6367 _ -.0688933670 (Answer)
-86,536
0 1 J 3 4 5 I 7 8 9 A B C D E F
OIL 0000 0001 0001 0003 0004 OOOS oooe 0007 oooe 0009 0010 0011 0012 0013 0014 0015
OL 0011 0017 0018 0019 OO!O 0021 0022 0023 0024 0025 00J8 0027 0028 0029 0030 0031
Ol.. 0032 0033 0034 0035 0031 0037 0038 0039 0040 0041 0042 0043 0044 0045 0046 0047
03_ 0048 0049 OOISO 0051 0052 0053 00S4 0055 0058 0057 0058 0059 0060 0061 0062 0013
OL 0014 OOIIS 0088 0087 0018 0089 00'70 00'71 00'72 00'73 00'74 00'75 00'76 00'77 0078 0079
05_ 0080 0061 008i 0083 0084 0085 0088 0087 0018 0089 0090 0091 0092 0093 0094 0095
08_ 0088 0097 0098 0099 0100 0101 0101 0103 0104 0105 0106 0107 0108 0109 0110 0111
07_ 0112 0113 0114 0115 0116 0117 0118 0119 0120 0121 0111 0113 0124 0125 0128 0127
08_ OIlS 01. 0130 0131 0132 0133 0134 0135 0138 0137 0138 0139 0140 0141 0142 0143
09_ 0144 .0145 0146 0147 0148 0149 0150 0151 0152 0153 0154 0155 0156 0157 0158 0159
OA... 0160 0161 0161 OUJ3 0184 0165 0166 0117 0168 0189 0170 0171 0172 0173 0174 0175
OB_ 0176 0177 0178 0179 0180 0181 0182 0183 0184 0185 0186 0187 0188 0189 0190 0191
OCL 0192 0193 0194 0195 0196 0197 0196 0199 0200 0201 0202 0J03 0204 OJOS 0J06 0J07
OD_ 0J08 0209 0110 0111 0112 0113 0114 0115 0116 0117 0118 0119 0J20 0121 0JJ2 0223
OE.- 0J24 0J2S 0J2I 0J27 0JJ8 0J29 0J30 0131 0132 0J33 0234 0J3S 0238 0J37 0J38 0J39
OF_ 0J40 0241 0J42 0J43 0J44 0J4S 0J46 0247 0J48 CY..49 0J50 0251 0252 0253 0JS4 OJSS
10_ 0IS6 0JS7 0JS8 0259 0260 0211 0J62 0183 0J64 0J6S 0JfJ6 0JI7 0J68 0J89 0170 0171
IL OI7J 0173 0174 0175 0171 0J77 0278 0179 0J80 0281 0J82 0J83 0J84 0J8S 0286 0J87
lL 0J88 0J89 0J90 0191 0292 0293 0J94 029S 0J96 0297 0J98 0J99 0300 0301 030J 0303
13_ 0304 030S 0308 0307 0308 0309 0310 0311 0311 0313 0314 0315 0311 0311 0318 0319
It.. 0320 0321 032J 03J3 0324 0325 0321 0327 0318 0319 0330 0331 0332 0333 0334 033S
15_ 0338 0337 0338 0339 0340 0341 0342 0343 0344 034S 0346 0347 0346 0349 0350 0351
16_ 0351 03S3 03S4 03SS 03S6 03S7 03S8 0359 0360 0381 0382 0383 0364 036S 0368 0387
17_ 0388 0389 0370 0371 0371 0373 0374 0375 0376 0377 0378 0319 0380 0381 0382 0383
18_ 0364 038S 0386 0387 0388 0389 0390 0391 0392 0393 0394 039S 0396 0397 0398 0399
19_ 0400 0401 040l 0403 0404 040S 0408 0407 0408 0409 Otl0 0411 0411 0413 ()n4 0415
lA... Ot16 Ot17 0418 0419 0420 0421 04J2 0413 0424 0425 0G8 04J7 041S 0419 0430 0431
IB_ 0432 0433 0434 043S 0438 0437 0438 0439 0440 0441 0442 0443 0444 044S 0446 0447
1C_ 0448 0449 0450 0451 04S1 04S3 04S4 04SS 04S6 04S7 04S8 04S9 0460 0461 0482 0463
ID_ 0464 046S 0466 0417 0468 0489 0410 0471 0471 0473 0474 0475 0476 0471 0478 0479
1