Ken Shirriff's blog

The instruction set of the 8085 microprocessor has an underlying structure that becomes much clearer if expressed in an octal-based table,...

The 8085 microprocessor has two undocumented status flags: V and K. These flags can be reverse-engineered by looking at the silicon of the ...

The arithmetic-logic unit is a fundamental part of any computer, performing addition, subtraction, and logic operations, but how it works i...

The 8085 processor uses a PLA (programmable logic array) to control much of the activity within the processor, such as instruction decoding ...

In this article, I show how overflow is computed in the 6502 microprocessor at the transistor and silicon level. I've discussed the mat...

The overflow flag on the 6502 processor is a source of myth and confusion. In this article, I explain signed and unsigned binary arithmetic...