This appears to be a repost, perhaps not by the op but due to a glitch somewhere, of a question posted about a month ago and answered.
<[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > We are working on a project to decipher a record structure of an old > accounting system that originates from the late80's mid-90's. > We have come across a number format that appears to be a "float" but > doesn't match any of the more standard implementations. > so we are hoping this is a recognizable number storage format with an > identifiable name AND pre-built conversion method > similiar to the "struct" modules available in python. > > Here is what we have determined so far. > > Example Number: 1234567890 > > This get stored on disk as 8 bytes, resulting in the following HEX > characters; > 00 00 00 A4 05 2c 13 9f > > If we changed the order so that it is "little Endian" we get; > 9F 13 2c 05 A4 00 00 00 > > If the HEX is converted to binary it looks like; > 10011111 00010011 00101100 00000101 10100100 00000000 000000000 > 00000000 > > If the example number 1234567890 is converted to binary it looks like; > > 10010011 00101100 00000101 1010010 > > To extract the example number, you need to do the following; > 1) take the decimal value of the first byte and subtract 128 > 2) This tells you how many of the following bits to are significant and > must be read > 3) Once the remaining bits are read, reverse the first bit of that > group (ie if it is a 0 make it a 1) > 4) convert the result to decimal > ... and presto, the example number ! > > Using a fixed width font it is easy to see the match at the bit level; > > 10011111 00010011001011000000010110100100000000000000000000000000 > -------- 1001001100101100000001011010010 > > > If you are interested, the following are three other examples; > > Orig Hex: 00 00 00 60 92 96 72 A0 > Actual Value: 4069954144 > > Orig Hex: 00 00 80 22 A3 26 3C A1 > Actual Value: 6313297477 > > > So ... does anyone recognize this ?? > Is there a "built-in" conversion method in Python ?? > > Thanks in advance. > > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
