pop Instruction not supported in 64-bit mode using NASM?

Question

I\'m working on a more indepth hello world using NASM following this tutorial (section 4). This tutorial essentially teaches you how to handle command line input.
This is th

Answer 1

Yes, the 64-bit pop instruction is... POP. :-) You need to use it against 64-bit registers though (like rbx).

Answer 2

basically you can convert it into 64bit by replacing eax to rax (same goes for all other registers)