About Piston Assembler Piston X86-64 Assembler (PASM) is NASM syntax based symbolic machine code compiler for X86-64 architecture - fully working in browser and in Node.js based environments. Written in CoffeeScript (and compiled to JavaScript) during the rainy finnish summer holiday. Current Features X86-64 opcodes NASM syntax 16,32,64 bit modes R8-R13 registers SIB, MODR/M, RIP addressing EQU, T