X86 Assembly/Programmable Parallel Interface
- This section of the x86 Assembly book is a stub. You can help by expanding this section.
The Original x86 PC had another peripheral chip onboard known as the 8255A Programmable Peripheral Interface (PPI). The 8255A, and variants (82C55A, 82B55A, etc.) controlled the communications tasks with the outside world. The PPI chips can be programmed to operate in different I/O modes.