Bits and logic for Eng101

A number of you have asked for some written source for the material we have been coverring in class. I've found some pretty good basic sources for the material. In many cases it goes into a bit more detail then we have, but I think it is all quite readable.

Binary representation, addition, subtraction. This also covers multiplication and division which you may ignore.
Signed number representation. You can entirely ignore the 1's complement stuff. The excess representation may come up later so you might want to look at that.
Signed and floating-point numbers. This is a lot more detail then you need, but a nice resource.
Using logic to do addition. Assumes you know what an xor gate is.