[Mesecons] 4bit ripple carry adder

[DuSt]

Here is a 4bit ripple carry adder only using 'and', 'xor', 'nand' and 'not' gates.

There is a full-adder in every layer. This full-adders are constructed by two half-adders. And these half-adders are made by an 'and'-gate and a 'xor'-gate. The half-adders are connected by an 'or'-gate. The 'or'-gate is simulated by a 'nand' and a 'not'-gate.

Have Fun! :-)



Download: http://www.xup.in/dl,12902755/4bit-adder.zip/

[Temperest]

Impressive.

Suggestion: you can save space by using an XOR gate to connect the two half adders rather than a NAND gate and two NOT gates (from what I gleaned from your post).

Also, you don't need to power switches; they generate their own power when you turn them on.

And of course, there are microcontrollers. With microcontrollers, it's possible to make the adder in a 4x5x4 area.