binary numbers

[FrozenLight]

Where can I find a routine that converts a number in bcd or ascii format to binary. (For large numbers (50-digit))?

 

[AmkG]

You don't need a routine if you're using Intel microprocessors, you just need to learn about AAM and AAD...

Unfortunately BCD is a little harder... "Information has a tendency to be free. Which means someone will always tell you something you don't want to know."

 

[FrozenLight]

I don't see how those instructions (aad..) can simply convert my 50-digit number(unpacked decimal) into binary format. My approach was to devide the number by 2 then with the remainder decide wheter the first bit is 0 or 1. Then take the result and redivide by two to set the secound bit.
I continue this process until the original number is 0.
My problem is that the routine gets hard to do and I woundered if there was a simpler method.
Thanks

 

[AmkG]

A 50-digit unpacked decimal? Didn't see that, my bad.

You know why intel calls unpacked BCD 'ascii'? Because if you take a number in ASCII string form, and subtract 48 from each character, reverse the order of the digits, you get an unpacked BCD.

47532
is ascii...
34h 37h 35h 33h 32h
is unpacked BCD...
02h 03h 05h 07h 04h

Sounds like you need a simple ascii->int converter with the ability to work with n-digits... where n is 50.

What you do is, you take the LAST BCD digit, add it to a variable accumulator (which you init'ed to 0) then you go to the next last BCD digit and load it temporarily somewhere (say X), multiply the variable accumulator by 10, add X, then loop to the next next last BCD digit until you reach the 0th digit.

ACC=0
COUNTER=49
loop1:
if COUNTER<0, jmp outloop1
ACC=ACC*10
ACC=ACC + BCDNUMBER[COUNTER]
COUNTER=COUNTER-1
jmp loop1
outloop1:

50-digit decimal, that's beyond the range of 32-bits... you need to work with 64-bits, maybe 96-bits.
&quot;Information has a tendency to be free. Which means someone will always tell you something you don't want to know.&quot;