subtracting two binary numbers...

[simrantogether]

what is the best way of 'subtracting any two values in binary forms - using borrowing method' - without using 2's complement...

Regards,

Simran

 

[Pommie]

A=B-C.

Mike.

 

[Ratchit]

what is the best way of 'subtracting any two values in binary forms - using borrowing method' - without using 2's complement...

Regards,

Simran

Perhaps you would like to give some example problems. If a negative number is already in twos comlement form, then how are you going to not deal with twos complement?

Ratch

 

[simrantogether]

Well i got the answer but still ... as an example i give

you would like to give some example problems.

is:

1000010000- 0000000111 = 1000001001

Regards,

Simran

 

[Pommie]

You subtract them the same way you would in base 10. Start in the right column with 0-1 and borrow 2 from column two.

Like this,

.

Mike.

 

[Ratchit]

This is very informative.

https://teaching.idallen.com/dat2343/10f/notes/040_overflow.txt

Ratch

 

[simrantogether]

i'm unable to find the answer... if anybody can help... (subtracting in binary form)...

100100100 - 000011011 = ?

i'm getting answer as : 100000001 which when verified comes wrong... (using borrowing method)...

 

[Pommie]

Here you go,

292-27=265

Mike.

 

[simrantogether]

thanks and sorry to everyone who tried to make me understand... but i still didnt got....

well, everything is OK. ... anyhow...

,

Simran

 

[unclejed613]

wow... my first thought was subtraction could be accomplished by XOR.... nope.... it's been too long since i've done any binary math in that much detail (outside of the occasional subnet mask math).

 

[wkrug]

In Wikipedia is an interesting solution with hardware:
https://de.wikibooks.org/wiki/Digitale_Schaltungstechnik/_Subtraktion
Sorry in German, but it should can be found in english too.