Binary division

Scrolion

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Oct 28, 2019
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Hello, good day to you all. This is my first time here.
I have a question regarding binary devision where I need to devide a negative binary number with a positive devisor.

I tried using the twos complement to do it but then the value is really really weird.

The question:
Devide -145 / 3 in binary using 12-bit words and twos complement notation.

Suppose I'll get 11 and some decimal point value or 1011, but I get a really huge number when I use twos complement to solve this question....

Could I know where did I get it wrong?
 

Dr.Peterson

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Please show your work and result, so we can see what you might have done wrong.
 

Scrolion

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Oct 28, 2019
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Greeting sir, thank you for replying my question.
Currently, this is all I got. I have no idea where should I do after this step....
Thanks in advance.

IMG20191029135138.jpg
 

Dr.Peterson

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So you are dividing by 13, not by 3 as you said originally?

I would do what you would do in base ten: Divide the absolute values (145 / 13), and then change the sign of the quotient as needed.

If you were explicitly told to perform this operation "using 12-bit words and twos complement notation" as you say, then you must have been taught a specific algorithm. Looking for such an algorithm, I ran across this page, which says at the end, "Can convert the operands to their absolute values, perform the division, and then negating the result if the signs of the operands are different. Most contemporary architectures implement more sophisiticated algorithms for multiplication and division of Two's Complement numbers. Beyond the scope of this course!"

That is, a direct algorithm for such a division is something different from what you do on paper. What have you been taught about this?
 

Scrolion

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Oh my bad sorry, that's an error on my side 😅. Ya, the question is -145/13 not -145/3. Oh, then I'm really doing it wrong. Thank you very much Sir for helping me and sorry for the error on my question.
 

Dr.Peterson

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If you can show us what algorithm you have been taught in your course, we may be able to help with that. Do you have any examples of such a division?
 

Scrolion

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impossible as it might sound, our teacher didn't give us any example on dividing a negative number in binary.....
 

Dr.Peterson

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Do you have a textbook?

If you haven't been told what it means to "divide in binary using 12-bit words and twos complement notation", then you can't be expected to do it! Ask your teacher.
 

Scrolion

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Do you have a textbook?

If you haven't been told what it means to "divide in binary using 12-bit words and twos-complement notation", then you can't be expected to do it! Ask your teacher.
Well, I have asked my teacher about this question through Whatsapp (since it's holiday), but its been a few days and there's still no reply from her.....😅
 

Subhotosh Khan

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Well, I have asked my teacher about this question through Whatsapp (since it's holiday), but its been a few days and there's still no reply from her.....😅
Do you have a textbook? - It must have similar example problems!
 

Scrolion

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Oct 28, 2019
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Do you have a textbook? - It must have similar example problems!
Sadly no, we don't have any textbook for this subject. Our teacher only gave us slide show as a reference and I didn't found any example regarding signed binary number division in that slide show....
 

krimzondeleeuw

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Nov 19, 2019
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Sadly no, we don't have any textbook for this subject. Our teacher only gave us slide show as a reference and I didn't found any example regarding signed binary number division in that slide show....
Wow, sounds like your authorities are taking advantage of you. (Just a little bit that is.)
 
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