You can think of your numbers as fixed point. This implies especially 
that the precision is limited. So to convert, you can figure in a fixed 
multiplier, eg:

xx.yy  = 0XXYY/100 -> you store 0XXYY 2
xxx.yy = XXXYY/100 -> you store XXXYY 2
xx     = 0XX00/100 -> you store 0XX00 0
x.y    = 00XY0/100 -> you store 00XY0 1

thus the decimal point 'disappears' for internal conversion and 
comparison purposes (you store 0XXYY), but you store is away and use it 
later for display. You have to store the requested precision (number of 
digits after . entered) along with the encoded request. Then when you 
display a number you do:

0XXYY 1 -> zXX.Y

z is a suppressed leading zero, XX are the integer part, you print a dot 
iff the original string had a dot, and as many Y's as Y's were in the 
original string after the dot (and suppress the others).

To store and compare data easily in internal form you can use the binary 
form of XXXYY. Multiplying binary values by d'100' is easy (as long as 
you do not ever need to divide). If you have enough storage you can use 
the decimal form (f.ex. unpacked BCD) for arithmetics. This makes for 
low cost conversion for display on multiplier-less micros.

I hope that this makes sense. It's 3AM here.

Peter




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