Not
// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.
// File name: projects/01/Not.hdl
/**
* Not gate:
* out = not in
*/
CHIP Not {
IN in;
OUT out;
PARTS:
// Put your code here:
Nand(a=in, b=in, out=out);
}

And
// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.
// File name: projects/01/And.hdl
/**
* And gate:
* out = 1 if (a == 1 and b == 1)
* 0 otherwise
*/
CHIP And {
IN a, b;
OUT out;
PARTS:
Nand(a=a,b=b,out=iphone);
Not(in=iphone,out=out);
}

Or
// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.
// File name: projects/01/Or.hdl
/**
* Or gate:
* out = 1 if (a == 1 or b == 1)
* 0 otherwise
*/
CHIP Or {
IN a, b;
OUT out;
PARTS:
Not(in=a, out=oa);
Not(in=b, out=ob);
Nand(a=oa, b=ob, out=out);
}

Xor
// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.
// File name: projects/01/Xor.hdl
/**
* Exclusive-or gate:
* out = not (a == b)
*/
CHIP Xor {
IN a, b;
OUT out;
PARTS:
// Put your code here:
Or(a=a, b=b, out=oab);
Nand(a=a, b=b, out=nab);
And(a=oab, b=nab, out=out);
}

Mux
// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.
// File name: projects/01/Mux.hdl
/**
* Multiplexor:
* out = a if sel == 0
* b otherwise
*/
CHIP Mux {
IN a, b, sel;
OUT out;
PARTS:
// Put your code here:
Not(in=sel, out=osel);
And(a=a, b=osel, out=sel1);
And(a=b, b=sel, out=sel2);
Or(a=sel1, b=sel2, out=out);
}

DMux
// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.
// File name: projects/01/DMux.hdl
/**
* Demultiplexor:
* {a, b} = {in, 0} if sel == 0
* {0, in} if sel == 1
*/
CHIP DMux {
IN in, sel;
OUT a, b;
PARTS:
// Put your code here:
Not(in=sel, out=osel);
And(a=in, b=osel, out=a);
And(a=in, b=sel, out=b);
}
