Intel's 486 was a processor (CPU, the main chip that drives your PC) that was very popular in PCs in the early to mid-1990s. Several versions were made, with the two most notable being the 486SX and the 486DX. The main difference between these two was the presence of a Floating Point Unit, which speeds up certain calculations. The 486SX didn't have it, and was therefore quite a bit cheaper than the full-blown 486DX. Both were available in several clock speeds, with 25 and 33 MHz being the most common.
This is the bottom of a 486SX-25. There was a metal lid over the chip, which came off simply by heating.
One detail of the circuit. It's obvious that this is a high-tech piece of engineering: the individual wires are barely visible. The 486 was made in a 1.0 micron process, which means that the transistors are one micron wide, or one-thousandth of a millimetre. There are about one million transistors on this CPU.
This is probably a bit of memory. You can recognize memory by a large area of regular, identical horizontal and vertical lines.
Yes, these shiny yellow wires at the top are actually made of gold! Gold wires are used very often to connect chips to the outside world, because gold can very easily make a reliable connection to the pads on the IC.
The chip's name, manufacturer and copyright dates are displayed here, in the middle of a busy intersection of wires and buses.
The top-left corner. Again lots of wires, of varying thickness. I have no idea what this 'HI'-shaped thing in the corner between the bondwires is.... anyone?