to perform U/V where these are bcd floats. first unpack the mantissas, exponents and signs so that you have two positive mantissas u/v. start by settings the exponent of the result, w, to be exp(U) - exp(V). now perform the u/v division as follows:
(1) ensure that u >= v. if not, shift u left 1 packed bcd digit and decrement w, if quotient = 0, otherwise shift quotient left 1 digit.. goto (1)
(2) while u >= v, perform u = u - v. count the number of subtractions, q. this is the next digit of the answer. goto (1)
there’s a bit more to it than this but essentially you are shifting until you’ve got something to subtract then you subtract all you can at each digit and put the number of subtractions into the answer and continue until you’ve got a full house of quotient mantissa.
lastly fix up the signs and exponent of the quotient.
i wrote some `C’ code one for this here:
http://www.voidware.com/bcdfloats.htm
