What is it?

A module for the RC2014 Z80 computer which adds MIDI IN and OUT with standard 5-pin DIN sockets. It comes with a code framework (Z80 assembly and C) and some built examples.

Why did you make it?

I made it because I enjoy programming the RC2014, enjoy making music and love MIDI. I use the AY and SID modules for RC2014 and thought it would be fun to control those using a MIDI controller such as a keyboard or sequencer. Or to write a sequencer with keyboard input. The possibilities are endless!

What makes it special?

If you've seen this product before, the first version did not have its own serial and relied on the computer's second port. For Retro Challenge 2024 I decided to make the Mk2 (which is what I'm offering here). It has its own serial chip and therefore is more 'plug and play' than the previous version. My blog post about the development is here: https://newstuffforoldstuff.blogspot.com/2024/09/rc202410-my-entry.html

I have written a simple API for receiving and sending MIDI (simple if you write z80 assembly or C ). The framework uses interrupts and buffering to make sure that there are no missed bytes with the incoming MIDI. (I have not yet got interrupts working with ROMWBW, so on that system it's necessary to poll the data port frequently.)

Currently, these systems are supported:

• 32k (Classic, Mini and Micro with 32k ram starting at $8000, ACIA serial and SCM OS)
• CP/M (Pro machines running CP/M with SIO2 serial)
• CP/M (machines running CP/M with ACIA serial, eg CP/M-upgraded Mini or Classic II)
• ROMWBW (booted into CP/M or Z-system with SIO2 serial.

There is a limited library of code and example programs but I am working on more and could add programs that others write and want to share.