Integer Base Conversion Tool

This page contains a proof of concept demo and code for some integer base (radix) conversion algorithms. The algorithms used are crudely described in Alternative Algorithms for Integer Base Conversion. DispConWeb is a web based java calculator for integer base conversion. It handles positive integers in positive and negative bases from base -94 through 94, except for bases -1, 0 and 1.

Here are the values for the digits used... 0 1 2 3 4 5 6 7 8 9 0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz`~!@#$%^&*()-_=+[]{}\|;:,.<>/?'"

Here is the java applet...

Notes: 'A' and 'a' have different values (10 and 36) as do all upper/lower case alpha character pairs. There is very little validation, so it's up to you to avoid overflows. Positive integers only... The dot ('.') is the 89th digit (value=88 if abs(base) > 89), not a radix point. Numerals which start with a dash ('-') start with the 74th digit. They are not negative. Numbers in negative bases are negative if their number of digits is even. Bases which start with a dash ('-') ARE negative.

Source: DispConWeb.java - Applet I/O and error checking stuff. Normalize.java - Inbase is a multiple/factor of outbase. PascalT.java - Convert between bases by an additive offset, using Pascal's Triangle.

Local Version: DispCon (stale and gettting staler 6/9/7)

Author: Steve Palmer (remlaps@ccil.org)

June 1, 2007
Revised June 9, 2007