- Warsaw, officially the Capital City of Warsaw, is the capital and largest city of Poland. The metropolis stands on the River Vistula in east-central Poland. Its population is officially estimated at 1.86 million residents within a greater metropolitan area of 3.27 million residents, which makes Warsaw the 7th most-populous city in the European Union. The city area measures 517 km2 (200 sq mi) and comprises 18 districts, while the metropolitan area covers 6,100 km2 (2,355 sq mi). Warsaw is classified as an alpha global city, a major cultural, political and economic hub, and the country’s seat of government. It is also the capital of the Masovian Voivodeship.
- Reverse-engineering the 8085’s decimal adjust circuitry (righto.com)
In this post I reverse-engineer and describe the simple decimal adjust circuit in the 8085 microprocessor. Binary-coded decimal arithmetic was an important performance feature on early microprocessors. The idea behind BCD is to store two 4-bit decimal numbers in a byte. For instance, the number 42 is represented in BCD as 0100 0010 (0x42) instead of binary 00101010 (0x2a). This continues my reverse engineering series on the 8085’s ALU, flag logic, undocumented flags, register file, and instruction set.