- Down to the silicon: how the Z80’s registers are implemented (righto.com)
The 8-bit Z80 microprocessor is famed for use in many early personal computers such the Osborne 1, TRS-80, and Sinclair ZX Spectrum. The Z80 has an innovative design for its internal registers, with two sets of general-purpose registers. The diagram below shows a highly-magnified photo of the Z80 chip, from the Visual 6502 team. Zooming in on the register file at the right, the transistors that make up the registers are visible (with difficulty). Each register is in a column, with the low bit on top and high bit on the bottom. This article explains the details of the Z80’s register structure: its architecture, how it works, and exactly how it is implemented, based on my reverse-engineering of the chip.
- Swinomish Reservation (Wikipedia)
The Swinomish Indian Reservation is the reservation of the Swinomish Indian Tribal Community, located on Fidalgo Island in western Washington state. The western boundary of the reservation is disputed between the Swinomish Tribe and the United States government. De facto, the reservation is around 15 square miles (39 km2; 9,600 acres) in size. It comprises a substantial portion of the eastern portion of Fidalgo Island. The total reservation population in 2000 was 2,664.