- Reverse-engineering the 8086’s Arithmetic/Logic Unit from die photos (righto.com)
The Intel 8086 processor was introduced in 1978, setting the course of modern computing. While the x86 processor family has supported 64-bit processing for decades, the original 8086 was a 16-bit processor. As such, it has a 16-bit arithmetic logic unit (ALU).1 The arithmetic logic unit is the heart of a processor: it performs arithmetic operations such as addition and subtraction. It also carries out Boolean logic operations such as bitwise AND and OR as well as also bit shifts and rotates. Since a fast ALU is essential to the overall performance of a processor, ALUs often incorporate interesting design tricks.
- Fort Steilacoom (1849-1868) (historylink.org)
Fort Steilacoom, located in south Puget Sound near Lake Steilacoom, was established by the United States Army in 1849. Protection of settlers in the area had become an issue. As well, the United States was anxious to plant the flag on land claimed by Britain. (Britain had ceded the territory south of the 49th parallel in 1846, but claimed this land as a commercial enterprise. Fort Steilacoom was established in what was then Oregon Territory. Congress would create Washington Territory in 1853.) In August 1849 the U.S. Army moved onto the Joseph Heath farm to establish the fort, leasing the land from the British Hudson’s Bay Company. The fort served as a headquarters in the 1855-1856 Indian Wars, but there were no hostile actions here. A major event was the incarceration of Nisqually Chief Leschi (1808-1858) in the fort guardhouse. The post commander and other officers protested his trial and murder conviction, arguing that he was probably not guilty, as a state of war had existed. Fort Steilacoom was closed in 1868 and became the site of the Western State Hospital, a psychiatric facility. Today (2012) the Fort Steilacoom Museum is also located on the site.