That's funny... I've had a Compaq Portable III for years and didn't know the keyboard was removable. It looks hard-wired because there's a little plastic cover over the port. (...probably a bad idea for me to remove it to find out. It was a bit of a bastard to put it back together and the cracked cable disintegrated.)
This keyboard is pretty mushy to type on. If it isn't a rubber dome, it sure feels like one.