Back in the late 1990s, digital sound capabilities had become standard equipment on PCs. And when equipment becomes standard, cheap versions become available so that everyone can join the crowd. Crystal (owned by Cirrus Logic) was one manufacturer that made many 'low cost audio solutions', one of which is the CS4236. I found this chip on a Dell motherboard sporting a Pentium 166 processor.

This chip was made in 1997. It connects to the ISA bus, which was still a standard feature on PCs in those days.



The inside. It's obvious that this is a high-tech chip, because we can hardly see the individual wires. Also note that there are many different colours, which is a side effect from having such small structures. These cause the light to reflect in a more complicated fashion than on simple chips.



The chip is divided into several distinct blocks. Each has a different function, and nowadays it often happens that chip makers just buy the blueprints for a load of blocks from various developers, wire them together and etch them onto a chip. This enables them to make very complex systems with a minimum of development cost.



It's amazing how many different shapes and colours fit on one chip...

It's very hard to see what each part does, these tiny things don't even look like transistors on this scale!



In this area we can see the manufacturer's logo, some type numbers, and a few test structures. These test structures contain huge transistors, by far the largest things on the entire chip :-)



I seriously have no idea what we're seeing here, but at least it looks pretty.



This area uses much more visible lines than the stuff around it.



Near the logo and model number I spotted this tiny little map of Texas :-) Does anyone know what 'D23' means?

A close-up of one of the test structures. This is an n-type MOSFET. The terminals on the left are the source and drain, the top right is the gate, and the bottom right terminal is connected to the substrate (also called "bulk").