Is there a assembly tester ?

Question

I mean something like a regular expression tester.

I could input the machine code and the software could verify/disassemble it to see whether the code is correct/what does the code represent.

I could also input the assembly and the software could also verify/assemble it to machine code.

It should have a GUI interface and run under Windows.

Answer 1

OllyDbg has a disassmbler and assembler. And also aalows you to edit bytes (machine code). And it's free.

Answer 2

gcc or gnu assembler (as) will assemble the code for syntax, very quick to check. then objdump to disassemble if you want to see the opcodes or whatever.