Help with implementing a 6 bits substractor with 74ls83

Thread Starter


Joined Jan 19, 2013
HI everyone, I;m new to the site. I need some help with this project, it's an implementation and to be honest don't know how to procede, so all feedback and help will be much appreciated.

panic mode

Joined Oct 10, 2011
read the datasheet.
74LS83 is a 4-bit adder. to work on 6 bit you will need two of them.
adding/subtracting is the same thing, you just need one of operands to be negative (2's complement)


Joined Feb 19, 2009
74LS83 Datasheet

You'll need two, as stated above. Pin 14 of first goes into pin 13 of the second. Decide which one is "Most significant nybble" (first hex digit) that one will have the Carry In.

Do you know how to convert binary to two's compliment for subtraction?