Using base 80 for compressing files I want to compress file size through making my own numbering system which is 80-based number, I do really want to know whether this even possible ? I learnt that Hexadecimal uses symbols like A, B, C, D, E, F to represent 10,11,12,13,14,15 -- and that's what i want to do to my own numbering system but in a bigger scale . Please correct me if i'm missing something .

Is it possible ?
While you will need fewer 80-based numbers than 2-based numbers (bits) to encode the same file, the only way to store these 80-based numbers on a computer is to encode them as bits. So you do not gain anything.

In fact you actually lose space, since 80 is not a power of 2: You will need 7 bits for each 80-based number, but in these 7 bits you could instead encoed 128 different states, if you used them directly.