Michael Steil has provided a late-edition C64 board for study. The CSG/MOS 8701 is a small DIP16 chip in the center of the board. Both Commodore and MOS names appear on the die.
1600 x 1948 JPG 1.76 MB
3977 x 4842 JPG 8.79 MB
3977 x 4842 JPG 806 kb
The image above is of the bare die after de-packaging. A map of the stitched images is on the right.
The topmost die shot is stitched from 20 separate microscope shots taken with a Nikon LV150 using an LU Plan Fluor 20x objective. The images were shot by Greg James in San Francisco, then corrected and stitched automatically by Christian Sattler in the UK, using
and custom code.
The 3977 x 4842 image is the full resolution stitch, not reduced because the die is very small.
Pavel Zima in Prague has done a great job annotating the various layers, and he's done this even before we've stripped away the upper layers. Here are his layer images, each 3977 x 4842 aligned to the surface image above. Another one of our members who goes by the username Quietust, has just started to run tools over these layer images, and we're working to correct a few issues in the images. Pavel is also working on a schematic included here as the last image.