Hi,

I have been working on a General MIDI-style setup for the Roland D-110.
This does not turn the D-110 into a true GM module. The D-110 predates General MIDI, has only 8 melodic Parts plus the Rhythm Part, and does not contain exact equivalents for all 128 GM instruments. The goal is simply to make standard GM MIDI files sound reasonably sensible on a D-110 by rearranging its preset tones into GM program order and correcting some of the more obvious incompatibilities.
This is currently version 10.

Reorders all 128 D-110 Timbres into approximately General MIDI Program 1–128 order.
Uses:
Part 1 → MIDI Ch.1
Part 2 → MIDI Ch.2
...
Part 8 → MIDI Ch.8
Rhythm → MIDI Ch.10
Creates a Patch named:
GM SETUP
Uses Patch slot I88 / A88.
Reverb is disabled.
Partial Reserve:
4, 4, 4, 4, 3, 3, 3, 2, 5
1, 2, 3, 4, 5, 6, 7, 8, R (corresponding parts)
Total = 32 Partials
Sets Pitch Bend Range to ±2 semitones for all 128 Timbres, includes a GM-ish rhythm/drum mapping, includes many octave corrections found by listening to all 128 programs using the same MIDI note.

One important problem is that many D-110 preset tones do not use the octave placement expected from later GM instruments.
For example, some basses originally sounded one octave too low, while some sounds such as Celesta, Pan Flute and Halo Pad were one octave too high.
V10 contains a fairly large set of individual Key Shift corrections based on listening tests.
Some examples:
Bass Programs 33–40 +12 semitones
Celesta -12
Pan Flute -12
Halo Pad -12
Distortion Guitar +12
There are also many additional individual corrections for electric pianos, guitars, strings, brass, saxes, leads, pads and percussion-type programs, the included text file contains the complete 128-program mapping and Key Shift values.

I haven't found an exact GM equivalent for D-110 that applies to all guitar types, so these are approximate values.
Programs 28–31 have been deliberately mapped to different D-110 tones so that Clean, Muted, Overdrive and Distortion Guitar do not all produce essentially the same sound.
Some GM sounds simply do not exist as equivalent D-110 presets, for example: GM #123 "Seashore" is currently approximated using D-110 b06 "Atmosphere", I can only do my best.

I strongly recommend using D-110 firmware v1.13.
My D-110 originally had:
v1.01 Mar. 22, 1988
With v1.01 I encountered severe SysEx / Patch / MIDI behaviour problems. Program Changes could be received, but melodic Parts would sometimes not respond correctly to Note On messages after loading the setup.
After upgrading the D-110 to v1.13, those problems disappeared completely.
Because of this, I would not recommend using this setup on very early D-110 firmware without first upgrading the ROM.

The release contains:
D110_GMISH_V10.MID
D110_GMISH_V10.SYX
D110_GMISH_V10_PATCH.txt > D110GM.ZIP

SPRING_OF_THE_NORTH.MID
SPRING_OF_THE_NORTH.MP3 > DEMO.ZIP

>D110_GMISH_V10.MID<
SMF Format 0 version. This is convenient for hardware sequencers such as the Yamaha MDF2 or normal MIDI playback software.

>D110_GMISH_V10.SYX<
Raw Roland D-110 DT1 SysEx data.

>D110_GMISH_V10_PATCH.txt<
Contains the complete Patch configuration, 128-program mapping, Key Shift values, Bender Range values and other notes.

>SPRING_OF_THE_NORTH.MID<
Demonstration song. Originally from Roland SMFs, has been translated to GM.

>SPRING_OF_THE_NORTH.MP3<
Recorded by playing D-110 that has been processed by this SysEx.

ABOUT LOADING THIS SYSEX
Before sending the file:
Memory Protect = OFF
Exclusive Unit Number = 17
Then send either the .MID or .SYX file to the D-110.
After transmission, manually select PATCH:
I88 / A88 GM SETUP
This SysEx deliberately does NOT send an automatic final Program Change to select the Patch.

The D-110 is still a D-110, so several GM features cannot be reproduced exactly.
In particular:
Only 8 melodic Parts are available (Part 1-8, 10 for rhythm).
Many GM sounds have no direct D-110 equivalent.
RPN-based GM behaviour should not be assumed.
Some sound effects are only rough approximations.
The rhythm set is GM-ish rather than a perfect GM drum kit.
This does not implement GM System On.
The intention is mainly to make normal GM MIDI files more usable on the D-110 while retaining the character of the LA synthesis engine.
I tested the octave placement by playing the same Middle C note through all 128 programs and correcting obvious octave errors individually.
More testing is welcome, especially if anyone has suggestions for better D-110 preset choices for the less accurate GM programs.

This is shared as a community experiment rather than a finished standard. If you find a wrong octave, a better preset choice, or a MIDI compatibility issue, please post your results.
Just for sharing my testing, thanks a lot for everyone.