Search for a tool
Excess-3 Code (Stibitz)

Tool for decoding/encoding numbers via the Stibitz code also called Excess-3, a binary digital system similar to the BCD code, used by old processors coding each digit on 4 bits.

Results

Excess-3 Code (Stibitz) -

Tag(s) : Informatics

Share
Share
dCode and you

dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day!
A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!


Team dCode likes feedback and relevant comments; to get an answer give an email (not published). It is thanks to you that dCode has the best Excess-3 Code (Stibitz) tool. Thank you.

Excess-3 Code (Stibitz)

Excess-3 Decoder/Converter



Excess-3 Encoder/Converter



Tool for decoding/encoding numbers via the Stibitz code also called Excess-3, a binary digital system similar to the BCD code, used by old processors coding each digit on 4 bits.

Answers to Questions

How to encrypt using Excess3 code?

The code Excess-3 (also called Stibitz code and sometimes shortcut XS3 or XS-3) is a 4-bit binary decimal code (like the BCD) created to optimize some calculations in base 10 on older processors.

The representation of a number in Excess-3 code is said to be biased because it has an offset of 3 (hence the 3 of XS-3) with the expected values and used by the conventional BCD code.

Example: 0 is coded 0011 in XS-3 whereas 0011 is 3 in BCD code.

The use of this offset allows a quick calculation trick for the complement to 9 (decimal) by inverting the bits, which is a big time saver for the calculation of subtractions by the processors.

Example: The digit 0 is coded 0011 in XS3 and its binary complement (inverting the 1's and 0's) is 1100 which corresponds to 9 in XS3.

The Decimal to Excess-3 conversion table:

DigitCode XS-3
00011
10100
20101
30110
40111
51000
61001
71010
81011
91100

Example: 123 is coded 0100,0101,0110

The codes 0000 or 1111 are not used to represent numbers, which can be interesting in the sending of communication (the sequences of 0 and 1 are often representative of reading errors)

How to convert a number coded in Excess3?

Splut the binary number into groups of 4 bits and replace each group with the corresponding number in the conversion table (above).

Example: 11001011 is split 1100,1011 and corresponds respectively to the numbers 9,8, so the conversion in decimal is 98

How to recognize a Excess3 coded number?

The code has a binary representation, it is not really distinguishable from another binary code (BCD, Gray, etc.) apart from its particularity to avoid sequences of more than 7 0000000 or 1111111.

Any reference to the old processors, calculators or electronic cash machine of the 70s is a clue.

When Excess-3 have been invented ?

George Stibitz created a calculating machine based on this principle in 1937.

Source code

dCode retains ownership of the source code of the script Excess-3 Code (Stibitz) online. Except explicit open source licence (indicated Creative Commons / free), any algorithm, applet, snippet, software (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or any function (convert, solve, decrypt, encrypt, decipher, cipher, decode, code, translate) written in any informatic langauge (PHP, Java, C#, Python, Javascript, Matlab, etc.) which dCode owns rights will not be released for free. To download the online Excess-3 Code (Stibitz) script for offline use on PC, iPhone or Android, ask for price quote on contact page !

Questions / Comments


Team dCode likes feedback and relevant comments; to get an answer give an email (not published). It is thanks to you that dCode has the best Excess-3 Code (Stibitz) tool. Thank you.


Source : https://www.dcode.fr/excess-3-code
© 2019 dCode — The ultimate 'toolkit' to solve every games / riddles / geocaches. dCode
Feedback