SID chip analysis

Here are some die shots of the SID chip. I hope they help in analyzing the filter section in particular. They were contributed by Chris Tarnovsky of Flylogic.

A lot of the mystery of the SID is in the parameters for the analog filter components. If you have specific measurements you want taken of the values here, please contact me.

6581-R2

This is an overview shot of the die, showing the three voice sections. The filter is at the top. This image is a little damaged and stitching screwed up the lower right corner. Still, it gives a good overview of the SID layout.

This is zoomed-in shot of just the D/A converter and filter sections. The D/A converter is at the very top left, between the 2nd and 3rd pins on the top edge. The filter is in the middle of the very top edge, between pins 4 and 5. There are some op amps here and resistors of unknown value.