- Inside the 8086 processor, tiny charge pumps create a negative voltage (righto.com)
Introduced in 1978, the revolutionary Intel 8086 microprocessor led to the x86 processors used in most desktop and server computing today. This chip is built from digital circuits, as you would expect. However, it also has analog circuits: charge pumps that turn the 8086’s 5-volt supply into a negative voltage to improve performance.1 I’ve been reverse-engineering the 8086 from die photos, and in this post I discuss the construction of these charge pumps and how they work.
- St. Peter Sandstone (Wikipedia)
The St. Peter Sandstone is an Ordovician geological formation. It belongs to the Chazyan stage of the Champlainian series in North American regional stratigraphy, equivalent to the late Darriwilian global stage. This sandstone originated as a sheet of sand in clear, shallow water near the shore of a Paleozoic sea and consists of fine-to-medium-size, well-rounded quartz grains with frosted surfaces. The extent of the formation spans north–south from Minnesota to Arkansas and east–west from Illinois into Nebraska and South Dakota. The formation was named by David Dale Owen (1847) after the Minnesota River, then known as the St. Peter River. The type locality is at the confluence of the Mississippi and Minnesota Rivers near Fort Snelling, Minnesota. In eastern Missouri, the stone consists of quartz sand that is 99.44% silica.