Program 16: 64-bit Math

Program 16: 64-bit Math

Binary long division #

If you remember back in middle school (elementary?), long division was one of those things where you probably just though, “can’t I use a calculator?” Can you do this with other bases other than 10? Absolutely. Welcome to long division, binary edition.

It’s actually pretty simple. Look at an example of 200/8.

         00011001 = 25
        __________
  1000 | 11001000
1:       1 
2:       11
3:       110 
4:       1100
        -1000
         0100
5:        1001
         -1000
          0001
6:           10
7:           100
8:           1000
            -1000

As opposed to re-inventing the wheel, Ben Eater has a great detailed video explaining how to do this with a computer. Video

Program 16: 64-bit Math Video

Description of Program

Multiply two 32-bit numbers. Take the result and write an integer to ASCII program that reads 64 bit numbers using this shift/long division method.

The two 32-bit numbers are 0xbf85be21 and 0xce0a6a80 and are already in the template.

Template/Input
Completed Code
Expected Output
11107400488765799040