GenMDM Version 2 PCB 5V Jumper Function

The GenMDM Version 2 PCB contains two main changes to the hardware compared with the Version 1 PCB. These changes are:

• A 5 pin DIN MIDI input connection with associated optocoupler and components
• A 5 volt jumper

The function of the jumper is as follows.

When the jumper is connected, as shows in the photo above, then the SEGA console will power the GenMDM hardware including the 5 pin DIN MIDI input connection.

Use this jumper in the connected position when using the GenMDM with a traditional 5 pin DIN connection. Do not use this jumper in the connected position when using the GenMDM with a USB cable at all. Never connect a USB cable to the GenMDM unit when the jumper is in the connected position. Doing so may damage the GenMDM.
 

When the jumper is disconnected, as shows in the photo above, then USB cable will power the GenMDM hardware. The 5 pin DIN MIDI input connection will not be powered, and a traditional 5 pin DIN connection will not work.

Use this jumper in the connected position when using the GenMDM with a USB cable for MIDI data or for firmware updates. This will provide 5V to the GenMDM hardware via the USB cable.

GenMDM PCB Version 1 Modification: SEGA Console Power

The GenMDM interface version 1 PCB can be powered from the SEGA console by performing this simple modification.

This modification will reduce noise in the audio output of the SEGA console, but it will also render the Teensy microcontroller board unable to be powered via USB cable alone.

This may make it unsuitable for people that wish to use their GenMDM Teensy boards for other things.

Take a GenMDM version 1 PCB.

Solder a wire to pin 5 of the 9-pin connector.

Solder the other end of the wire to the VCC pin header of the Teensy socket

Take your GenMDM Teensy. Note the underside. There is a series of three pads marked 3V 5V. Cut the trace that is between the middle pad and the pad next to the 5V sign. A clear diagram is given here.

This is the Teensy after the trace has been cut. Ensure that there is not connection between the two pads by using a multimeter to check resistance (or lack thereof).

Insert the Teensy board back into the cradle.

Express Shipping for GenMDM Orders - Available Now

If you have ordered a GenMDM unit and would like for the express shipping option, please: send AUD$12 via PayPal to seb.tomczak@gmail.com with your current address.

Note that this is *only* for people that have ordered a GenMDM unit already.

SEGA Genesis / Mega Drive YM2612 Register 2C "Loud Samples" Mode Demo

By switching a bit in register 2C of the YM2612 FM sound chip, samples are automatically boosted in amplitude by a massive amount. Below is an example video:

GenMDM v102 and above can access this register on MIDI channels 1 - 6 on CC 97. All distortion is created on the output of the SEGA console, as my sound card was not distorting.

GenMDM M4L Tools Updated - Now Includes TFI and TFI Folder Import!

The FM editor for GenMDM M4L Tools has been updated to include TFI import and TFI folder import. A TFI file is an FM instrument file from TFM Music Maker. Each TFI file is a single FM instrument. The "TFI" button imports a single TFI file.

The "TFI F" button imports up to 128  instruments from a folder containing 128 or less TFI files - e.g. a SEGA Genesis / Mega Drive instrument settings dump. These instruments are imported into the patch instrument menu. See below for usage examples!

Download all SEGA Genesis / Mega Drive TFI instruments with friendly names here: http://little-scale.com/GENMDM/TFI_SEGA_INSTRUMENTS/TFI_WITH_FRIENDLY_NAMES.zip . Many thanks to Chipmusic.org user Robugaa for importing and converting these files from the .OPM files.

Example of importing a single TFI instrument file:

Example of importing a folder full of TFI instrument files:

.GENM File Format: GenMDM Instrument Patch File Specifications

A .GENM file is used to store GenMDM patch files.

Each patch file can store up to 128 different instrument settings for an FM channel of a GenMDM interface.

A .GENM file is in a standard text format.

Each instrument is stored in the following way:
[Instrument Index], [Algorithm] [LFO FM] [LFO AM] [FM Feedback] [Panning] [OP1 Level] [OP2 Level] [OP3 Level] [OP4 Level] [OP1 Detune] [OP2 Detune] [OP3 Detune] [OP4 Detune] [OP1 Attack] [OP2 Attack] [OP3 Attack] [OP4 Attack] [OP1 Decay 1] [OP2 Decay 1] [OP3 Decay 1] [OP4 Decay 1] [OP1 Decay 2] [OP2 Decay 2] [OP3 Decay 2] [OP4 Decay 2] [OP1 Mul] [OP2 Mul] [OP3 Mul] [OP4 Mul] [OP1 Rate Scaling] [OP2 Rate Scaling] [OP3 Rate Scaling] [OP4 Rate Scaling] [OP1 Amp2] [OP2 Amp2] [OP3 Amp2] [OP4 Amp2] [OP1 Release] [OP2 Release] [OP3 Release] [OP4 Release] [OP1 LFO Enable] [OP2 LFO Enable] [OP3 LFO Enable] [OP4 LFO Enable] [OP1 SSG Data] [OP2 SSG Data] [OP3 SSG Data] [OP4 SSG Data] [Instrument Name Symbol String];

• Instrument index is indexed at 0
• Instrument index does not need need to be in order in the file
• TL is given as 127 - TL for each level parameter for each operator
• LFO enable is 0 for not enabled, 1 for enabled
• All other data fields are given as actual register data, not unscaled raw data
• Instrument name can be up to 256 characters long

Screencast: Batch Conversion Tool for TFI Instruments to GenMDM Patches

I made a batch conversion tool for converting many TFI FM instrument files to GENM instrument patches. Each TFI instrument file is just for a single instrument setting. GenMDM file patches are for up to 128 instruments per file. This allows for the conversion of the instruments from whole game sound tracks for convenient use with GenMDM.

You can download this tool here:

TFI2GENM source file: http://little-scale.com/GENMDM/GENMDM_APPS/TFI2GENM/TFI2GENM_SOURCE/TFI2GENM.maxpat.zip

TFI2GENM compiled for OS X: http://little-scale.com/GENMDM/GENMDM_APPS/TFI2GENM/TFI2GENM_OSX/TFI2GENM.zip

TFI SEGA Instruments with friendly names: http://little-scale.com/GENMDM/TFI_SEGA_INSTRUMENTS/TFI_WITH_FRIENDLY_NAMES.zip

Tanikugu GenMDM Introduction in Japanese

http://tanikugu.blogspot.jp/2013/01/midigenmdm.html

GenMDM Polyphonic Handling App

// GDAY M8s //

Normally, the GenMDM is monophonic i.e. each MIDI channel is directly mapped to a chip voice (1 - 6 for FM, 7 - 10 for PSG). As a result, each MIDI channel can only play one note at a time, as a single chip voice can only make one sound at a time.

Tonight I made a simple polyphonic handler for both the FM chip and the PSG chip of the SEGA Mega Drive. 

Usage is very simple: 

• Create a MIDI track in Live / Logic / ProTools / whatever

• Sequence a chord on this track with up to 6 notes

• Send the output of this track along channel 1 of a virtual MIDI bus (e.g. IAC MIDI bus 1 for OS X)

• In the GENMDM_POLY app, choose the same virtual MIDI bus as the input

• In the GENMDM_POLY app, choose the GenMDM as the output
• The level of polyphony for the FM and PSG chips are set by the user (2 - 6 voices for the FM and 2 - 3 voice for the PSG)

• Chords will automatically routed to GenMDM channels 1 - 6 without any effort whatsoever

• If you gave a stuck note, use the "KILL NOTES" button to stop it

• A chord with up to six notes should be routed to the FM chip via MIDI channel 1 (channels 2 - 6 should not be used)

• A chord with up to three notes should be routed to the PSG chip via MIDI channel 7 (channels 7 - 10 should not be used)

Download OS X application here: http://little-scale.com/GENMDM/GENMDM_APPS/GENMDM_POLY/GENMDM_POLY_SOURCE/GENMDM_POLY.maxpat.zip

Download Max patch here: http://little-scale.com/GENMDM/GENMDM_APPS/GENMDM_POLY/GENMDM_POLY_OSX/GENMDM_POLY.zip 

// THANKS FOR WATCHING && TREAD UR OWN PATH //

Sceencast: Prototype VGM Data Capture Tool for GenMDM

// GDAY M8s //

VGM files are files that contain register data for one or more sound chips. I've made a small app that records ALL GenMDM data register writes, and stores them as a .VGM file.

The idea is that SEGA Mega Drive music can be written using GenMDM + Live / Logic / ProTools / whatever and then distributed via .VGM files if desired as opposed to recording from hardware. 

For my own reference: 

• YM2612 register data is sent via MIDI CC,  as follows: 

• CC Number = address & 0x7E

• CC Value = data & 0x7E

• MIDI Channel = address & 0x80 >> 5 | data & 0x80 >> 6 |  page_number;

• i.e: B10110adp, B0aaaaaaaa, B0ddddddd

• SN76489 register data is sent via MIDI CC, as follows: 

• CC Number = data & 0x80 >> 1

• CC Value = data & 0x7E

• MIDI channel = B00001000

• i.e. B10111000, Bd0000000, B0ddddddd

// THANKS FOR WATCHING && TREAD UR OWN PATH //

How To: Add a 5-Pin DIN MIDI Input to GenMDM

Overview
GenMDM firmware 102 and above support an old style 5-pin DIN input running at 31250 baud. This is in addition to the USB MIDI input. Both can be used simultaneously.

This tutorial covers how to easily and quickly add a MIDI socket to the GenMDM hardware.

Materials Needed
In this tutorial, breadboarding will be used as this is easy, quick and doesn't require any soldering.

The following items are needed:

• GenMDM interface

• breadboard
• breadboard jumpers

• 4n28 chip
• 1n4148 diode
• 3.3kΩ resistor
• 100kΩ resistor
• 5-pin DIN socket

Step-by-Step Guide

1. Remove the Teensy board from the GenMDM interface PCB

2. Place the Teensy on the breadboard.

3. Place the 4n28 on the breadboard. In the diagram below, pins 3 and 4 are furthest away from the Teensy.

4. Connect 1n4148 diode between pins 1 and 2 of the 4n28 IC. The small stripe should be closest to pin 1.

5. Connect the 100kΩ resistor between pin 6 of the 4n28 IC and the ground bus.

6. Connect the 3.3kΩ resistor between pin5 of the 4n28 IC and the 5V bus.

7. Place the 5-pin DIN socket on the breadboard.

8. Connect the 5C VCC pin from the Teensy board to the 5V bus on the breadboard.

9. Connect the 0V ground pin from the Teensy board to the ground bus on the breadboard.

10. Connect pin 4 of the 4n28 IC to ground.

11. Connect pin 5 of the 5-pin DIN socket to pin 1 of the 4n28 IC.

12. Connect pin 4 of the 5-pin DIN socket to pin 2 of the 4n28 IC.

 13. Connect pin 5 of the 4n28 IC to digital pin 7 (the eighth pin on the left hand side) of the teensy

14. Connect the first pin of the GenMDM interface PCB to the first pin of the teensy board (i.e ground). 

15. Connect the second pin of the GenMDM interface PCB to the second pin of the teensy board.

16. Connect the third pin of the GenMDM interface PCB to the third pin of the teensy board.

17. Connect the fourth pin of the GenMDM interface PCB to the fourth pin of the teensy board.

18. Connect the fifth pin of the GenMDM interface PCB to the fifth pin of the teensy board.

19. Connect the sixth pin of the GenMDM interface PCB to the sixth pin of the teensy board.

20. Connect the seventh pin of the GenMDM interface PCB to the seventh pin of the teensy board.

21. Connect the eighth pin of the GenMDM interface PCB to the eighth pin of the teensy board.

How to: Update the GenMDM Firmware

1. Go to http://www.pjrc.com/teensy/loader.html and download the Teensy loader application for your operating system.

2. Locate and download the GenMDM firmware update file. This file will always have the name of GENMDM_NNN.cpp.hex, where NNN is the version number. The file type will always be .cpp.hex.

3. Open the Teensy loader application, and drag and drop the .cpp.hex file. You can also go to File > Open HEX File. 

4. Click on the 'Auto' button. 

5. Connect your GenMDM interface via a USB cable, and click the tiny black button on the top of the interface. If your GenMDM interface and SEGA is hooked up so that you can hear the sound, you should be able to hear the updated version loading sound. This indicates that the firmware has been loaded successfully!

GenMDM Firmware v100 Quick Reference MIDI Mapping

=====================================================================================
GenMDM Firmware v100 - Quick Reference MIDI Mapping by little-scale
http://www.little-scale.blogspot.com.au/
seb.tomczak@gmail.com
=====================================================================================
Firmware v100 Version Information: 
* Initial release
=====================================================================================
MIDI Channel Sound Chip Mapping
* YM2612 FM sound chip is mapped to MIDI channels 1 - 6. 
* SN76489 PSG sound chip is mapped to MIDI channels 7 - 10.
=====================================================================================
YM2612 FM Sound Chip Mapping
-------------------------------------------------------------------------------------
Parameter      CC  Data Range
* LFO Enable (Global)     74  2
* LFO Speed       1  8 
* Pitch Transposition     85  128
* Octave Division     84  128
* PAL / NTSC Tuning     83  2
-------------------------------------------------------------------------------------
Channel / Voice Control     CC  Data Range
* Preset Instrument Setting    9  16
* Frequency      Note Number 128
* Pitch Bend Amount     81  18
* FM Algorithm      14  8
* FM Feedback      15  8
* Stereo Configuration     77  4
* Amplitude Modulation Level    76  8
* Frequency Modulation Level    75  8
-------------------------------------------------------------------------------------
Operator Control      CC  Data Range
* Total Level OP 1     16  128
* Total Level OP 2     17  128
* Total Level OP 3     18  128
* Total Level OP 4     19  128
* Multiple OP 1      20  16
* Multiple OP 2      21  16
* Multiple OP 3      22  16
* Multiple OP 4      23  16
* Detune OP 1      24  8
* Detune OP 2      25  8
* Detune OP 3      26  8
* Detune OP 4      27  8
* Rate Scaling OP 1     39  4
* Rate Scaling OP 2     40  4
* Rate Scaling OP 3     41  4
* Rate Scaling OP 4     42  4
* Attack Rate OP 1     43  32
* Attack Rate OP 2     44  32
* Attack Rate OP 3     45  32
* Attack Rate OP 4     46  32
* First Decay Rate OP 1     47  32
* First Decay Rate OP 2     48  32
* First Decay Rate OP 3     49  32
* First Decay Rate OP 4     50  32
* Secondary Decay Rate OP 1    51  16
* Secondary Decay Rate OP 2    52  16
* Secondary Decay Rate OP 3    53  16
* Secondary Decay Rate OP 4    54  16
* Secondary Amplitude Level OP 1   55  16
* Secondary Amplitude Level OP 2   56  16
* Secondary Amplitude Level OP 3   57  16
* Secondary Amplitude Level OP 4   58  16
* Release Rate OP 1     59  16
* Release Rate OP 2     60  16
* Release Rate OP 3     61  16
* Release Rate OP 4     62  16
* Amplitude Modulation Enable OP 1   70  2
* Amplitude Modulation Enable OP 2   71  2
* Amplitude Modulation Enable OP 3   72  2
* Amplitude Modulation Enable OP 4   73  2
-------------------------------------------------------------------------------------
DAC Control (MIDI Channel 6)     CC  Data Range
* DAC Enable      78  2
* DAC Direct Data     79  128
* DAC Sample Pitch Speed    86  128
* DAC Sample Oversample     88  16
* DAC Noise  / Custom Wave Mode    89  2
* Custom Wave Byte 1 of 14    100  128
* Custom Wave Byte 2 of 14    101  128
* Custom Wave Byte 3 of 14    102  128
* Custom Wave Byte 4 of 14    103  128
* Custom Wave Byte 5 of 14    104  128
* Custom Wave Byte 6 of 14    105  128
* Custom Wave Byte 7 of 14    106  128
* Custom Wave Byte 8 of 14    107  128
* Custom Wave Byte 9 of 14    108  128
* Custom Wave Byte 10 of 14    109  128
* Custom Wave Byte 11 of 14    110  128
* Custom Wave Byte 12 of 14    111  128
* Custom Wave Byte 13 of 14    112  128
* Custom Wave Byte 14 of 14    113  128
===================================================================================== SN76489 PSG Sound Chip Mapping
* Global Control      CC  Data Range
* Pitch Transposition     85  128
* PAL / NTSC      83  2
-------------------------------------------------------------------------------------
Noise Channel Control     Type
* C and C#      High Frequency; Periodic Type
* D and D#      Medium Frequency; Periodic Type
* E       Low Frequency; Periodic Type
* F       High Frequency; Noise Type
* F#       Medium Frequency; Noise Type
* G and G#      Low Frequency; Noise Type
* A and A#      Channel 9; Periodic Type
* B       Channel 9; Noise Type
=====================================================================================

Available as a text file here: http://little-scale.com/genmdm_100.txt

GenMDM Screencast 01: Basic Hardware and Software Setup