8086 Emulation

Hey guys, Does somebody here know about a program I can use to emulate the original 8086-based computers? What I'm looking for is a program that can emulate (on either Dos, Windows or Linux): - The Intel 8086 processor - 640KB RAM - 360KB Floppy drive - Small hard drive (optional) - CGA graphics card Emulation of the IBM ROM BASIC, and IBM ROM BIOS, is also greatly desired, although, I am not sure whether these can be legally copied :-). Emulation of the IBM PC-DOS would also be helpful, but, yet again, I think this would result in copyright violation. I am pretty sure that emulating the CGA graphics card, a hard drive, a floppy drive or memory should not be a problem. Although, I'm not THAT sure about Intel's processor, but I think on Intel-based systems, this would only mean disabling certain newer instructions on the 80486/Pentium/whatever. Can somebody help me out here? Also, if there isn't something like this, how much trouble would it be to write one myself? Ciao, Lionel