Sunny fall day in Skyway
South border of William O’Brien- Silicon reverse engineering: The 8085’s undocumented flags (righto.com)
The 8085 microprocessor has two undocumented status flags: V and K. These flags can be reverse-engineered by looking at the silicon of the chip, and their function turns out to be different from previous explanations. In addition, the implementation of these flags shows that they were deliberately implemented, which raises the question of why they were not documented or supported by Intel. Finally, examining how these flag circuits were implemented in silicon provides an interesting look at how microprocessors are physically implemented.