Having now arrived in the 21st century, MIDIMATEs are no longer manufactured, nor does the company Hybrid Arts still exist in the form it once was. But there's still a strong community centered around the Atari 8-bit, with people like AtariAge member ivop creating his own MIDIMATE compatible solution called MIDI Muse. In his project as discussed HERE, ivop took it a step further and added built-in support for a MIDI Synthesizer Wave Table Module called the Dream Blaster S2. And although the project is presently on hold, it has been released on GitHub for those who wish to build one, or take it beyond it's present specification.
I was one of those people that decided to put my own twist on what ivop had created, and incorporated the idea into a new project started in 2018, known as the 1088XLD. But before I could actually do that, there was a lot to learn.
Through a series of experiments, and considerable help from ivop, my understanding of how MIDI works began to take shape and grow. Seeing that the serial communications baud rate for MIDI was a relatively slow 31,250 bits per second. It was decided that the glue logic which controlled the gating of the signals onto the SIO bus, could instead be accomplished as code running inside one of Microchip's 8-pin PIC micro-controller IC chips.
The first experiments with this new concept were highly successful, and led to other aspects being incorporated such as generating the external MIDI clock, and then later still a method of playing a little MIDI tune upon first powering-up the system. All made possible by the PIC MCU.
The first experiments utilized a 1088XEL as the test bed due to it having an AUX-SIO header, which made it very easy to connect to the SIO port. Luckily the header specification that came out of the early stages of MIDI Muse development, had everything that was required.
A series of boards resulted from these experiments. Some of which were throwaways, and others proved to be far more useful. One of those was the MIDI-XEL board that allowed the S2 module to be easily installed in the 1088XEL, bringing MIDI music in addition to the normal Pokey sound. This idea later got integrated into the 1088XLD.
Because of an inquiry from AA member Brentarian, a simpler less expensive MIDI interface board was also created. It's design working well with a multi-player game of MIDI-MAZE, supporting up to 16 systems in a MIDI Ring configuration. Thus the SIO2MIDI MIDIMATE compatible board was also born.
Michael St. Pierre
AtariAge Member: mytek
More to Come