See Wikipedia for good technical and historical information and references on the Motorola 6800.
We depackaged, deprocessed and photographed a later depletion-load version of the chip, which shows signs in the layout of the previous enhancement-load version. Ijor then captured polygons from the photos - here are JPEG images, which may be easier to explore than the svg format:
The recaptured polygon data closely resembles the original layout which defined the masks used to manufacture the chip, and is a great deal easier to study than the photographs.
Points of Interest
We've found these interesting features (more detail to be added):
- register circuit using resistive feedback and enhancement-style pullups
- data latch circuit using weak feedback transistor
- clock pulse shaping
- resistive bus pullup
- Manchester carry chain