What is it?

The Programmable peripheral interface (PPI), based on the 82C55A chip is a core part of the MSX spec and a necessary part of the MSX2014 project, which is an MSX1-compatible computer based on the RC2014 backplane. I am supplying this module assembled and tested and complete with a new 85C55A chip. Optionally I will send PCBs for my RAM/ROM and 'cartridge rom' modules. The reasons for this choice are given in my instructions on Hackaday.

Why did you make it?

The MSX was introduced in 1983 as a specification that various manufacturers could make. It had Microsoft BASIC, the powerful TMS9918A video chip and AY sound chip. As a fan of retro-computing, I wanted to build an MSX-compatible computer and the RC2014 seemed the perfect start.

What makes it special?

This may not be the cheapest or most compatible way to build an MSX computer (see also the 'yellow board' MSX and the Omega project) neither is it open-source. It is modular, giving you many options and allowing you to build it in stages. It also has compatibility with the RC2014, meaning that you can use many of the modules for that system such as digital i/o. My own instructions are staged, first adding the TMS video card by J B Langston and AY sound module by Ed Brindley. The next step is to add this PPI module with suitable selectable RAM and ROM modules and a keyboard which will create a working MSX computer.