Calling all EE's!

[blustori]

Hi I have a question. Lets say we have two numbers A and B with B being in compliment form. If I were to subtract A-B would I first have to take the compliment of B and then add or do I just subtract them directly? This is confusing. The notation is if you want to do A - B, then its the same as adding A + B with B being in compliment form.

 

[So]

Need more clarity in box.

 

[blustori]

bump

 

[Wonderful Pork]

what?

 

[blustori]

 

[edmundoab]

thats rather hard to get the question

 

[Merlyn3D]

um....you know there's 1's compliment then there's 2's compliment, and please try explaining it clearer, no one understands what you're saying

 

[blustori]

It could be 1's compliment or 9's compliment or any compliment... Nevermind.

 

[talyn00]

clarify your question. wtf compliment are you talking about?

 

[blustori]

Here let me make an example although I'm pretty sure I understand now. Lets say A = unsigned 0101 and B = signed 1001 with B already in 1's compliment form. Now if I were to do B - A, based on the notation, I would have to take the compliment of B and add it to A (same thing as B - A). My question was do you subtract directly or do you take the compliment of B when it is already in its compliment form and then add? Based on my thoughts, I am now very sure you ignore that B was in 1's compliment form and take the compliment of it anyway. Feel free to prove me wrong.

 

[crystal]

If I have to guess,

A - B = A + B

As for which compliment, you would have to convert B to B correctly.



P.S. Don't blame me if this is worng.