Yamaha YRM-102
This page was last modified 18:14, 7 December 2021 by Mars2000you. Based on work by Gdx and Rderooy and others.



The YRM-102 (YRM-12 in Japan) FM Voicing Program is the first version of the software developed by Yamaha to give precise control over the SFG digital FM voice generator, included in the MSX1/MSX2 CX computers. This software, released in 1983, was only available on cartridge. It allows to modify the pre-programmed voices 1 to 48 and create entirely new voices from scratch.

All data can be saved on cassette tape or data memory cartridge UDC-01. The YRM-102 software does not have disk support. The data and the list of all voices can also be printed (hardcopy of the screen).


YRM-102 Command menu

The YRM-102 software displays 4 main screens: the Command menu on which you land after the intro screen, the Directory (enter DI on the command line), the Edit mode that you can reach by pressing F1 and the Key list that is accessible by pressing F5.

The command line is available on all screens, except the key list. In the Edit mode, you need to press F1 to switch between this line and a block.

The green point on the line under the command line indicates the split point of the music keyboard between instrument 1 used in polyphonic mode for the editing keyboard and instrument 2 used in monophonic mode for the comparison keyboard. By default, this point is set at the lowest key, so it means that all keys are used for the editing keyboard.

To change the split point, you need to press SELECT, then a key on the music keyboard. The keys at the left of the green point will be used for the comparison keyboard. The current voice data are set for this keyboard by pressing F4 in the Edit mode.

Command menu (HE)

The screen of the Command menu is divided into 3 parts: a command line on which you can enter different commands, the list of the main available commands and the explanation of some abbreviations. Voice number can vary between 1 and 48.

Command Meaning
CL 'f' CLOAD ['filename'] Load data from cassette tape or data memory cartridge (UDC-01) (*)
CO n, m COPY voice number n, voice number m Copy data of voice n to voice m
CS 'f' CSAVE 'filename' Save data on cassette tape or data memory cartridge (UDC-01) (*)
DI DIRECTORY Go to the Directory screen
[ED] n EDIT voice number n Go to Edit mode for voice n (n can be replaced by + or -)
HE HELP Back to Command menu
KI n KILL voice number n Initialize voice n to create a new voice from scratch (original data are saved in the save buffer)
LO n, a LOAD voice number n, instrument number a Load voice n to instrument a (number a is 1 or 2)
MU MUSIC Go to the SFG-01 or SFG-05 synthesizer firmware
ON MOTOR ON Turn the motor of the tape recorder on
OFF MOTOR OFF Turn the motor of the tape recorder off
PR n, m PRINT voice number n, voice number m Print the data for voices n to m (hardcopy of screens)
RE RESTORE Replace the data of the currently edited voice by the data saved in the save buffer
RE n RESTORE voice number n Replace the data of voice n by the data saved in the save buffer
SA SAVE Save the data of the currently edited voice in the save buffer
SA n SAVE voice number n Save the data of voice n in the save buffer
SW n, m SWAP voice number n, voice number m Swap data of voices n and m

(*) ' = SHIFT + 7

Directory (DI)

YRM-102 Directory

The screen of the Directory is divided between the command line and a list of all of the names and numbers of the voices stored in the computer memory. By default, it's the list of the system voices.

This list can be different after loading of created voices from cassette tape or data memory cartridge, or switching to user voices in the SFG-05 firmware.

Access to the SFG-01 or SFG-05 firmware is indeed possible, by entering MU on the command line; you can then press twice on SELECT to switch between the system voices and the user voices if you are using the SFG-05 module. To go back to the FM Voicing Program, you need to press ESC in the synthesizer firmware.

Edit mode (F1)

YRM-102 Edit mode (F1)

The screen of the Edit mode is divided between the command line (access by pressing F1) and 5 blocks allowing to make a fine editing of the currently displayed voice.

General settings are in the first block, specific settings for each operator of the digital FM voice generator are in the 4 blocks with number 1 to 4. Use F3 to go to next block, F2 to go to previous block. The cursors are useful for selecting a parameter. To modify it, just type the new value and press RETURN.

Each of the 4 operators can be switched ON/OFF by pressing CTRL + one of the keys 1 to 4 corresponding to this operator. You can also move the cursor over the operator number and type in a different number to turn it OFF or the correct number to turn it ON.

General settings

Parameter Values
Voice Voice number 1 to 48 - Can't be modified
Code Personal code as memo for selecting a voice 0 to 99
Tr Transpose -128 to 127
LR Left Right Switch 00 (no output), 10 (left channel), 01 (right channel), 11 (both channels)
Ams Amplitude Modulation Sensitivity 0 to 3
Pms Pitch Modulation Sensitivity 0 to 7
Name Voice name Use BS for corrections before pressing RETURN !
Ne Noise Enable 0 (OFF, then change the keyboard split point) or 1 (ON)
Nf Noise Frequency 0 to 31 (press F4 after each change)
Al Algorithm 1 to 8
Fb Feedback (operator 1) 0 to 7
LFO Low Frequency Oscillator 0 (OFF) or 1 (ON)
Syc Synchronization of LFO to the playing of a note 0 (OFF) or 1 (ON)
Wf Waveform 0 (sawtooth), 1 (square), 2 (triangle), 3 (sample & hold)
Spd Speed (LFO frequency) 0 to 255
Amd Amplitude Modulation Depth (LFO influence on volume) 0 to 127
Pmd Pitch Modulation Depth (LFO influence on pitch) 0 to 127

Specific settings for each operator

Parameter Values Parameter Values
A Envelope generator - Attack Rate 0 to 31 IF Inharmonic Frequency 0 to 3
D Envelope generator - 1st Decay Rate 0 to 31 Dt Detune -3 to 3
S Envelope generator - Sustain Level 0 to 15 Ks Key Scaling Select 0 to 3
D Envelope generator - 2nd Decay Rate 0 to 31 Kd Key Scaling Depth 0 to 15
R Envelope generator - Release Rate 0 to 15 Rk Rate Key Scaling Depth 0 to 3
O Output Level 0 to 127 Vs Velocity Sensitivity 0 to 7
F Frequency 0 to 15 Aj Adjust 0 to 15

Key list (F5)

YRM-102 Key list (F5)

The Key list screen displays a list of the most important keys to be used with this software.

Besides the function keys, there are 3 specific keys for the velocity level, which can vary according the used music keyboard, and some combinations with the CTRL key.

The command line is not available on this screen.

Press on ESC to go back to previous displayed screen.

Here's a more complete list:

F1 Go to Edit Mode or switch between blocks and the command line in Edit mode
F2 Previous block in Edit mode
F3 Next block in Edit mode
F4 Load current voice data to instrument 2 for the comparison keyboard
F5 Go to the Key list
Cursors Select parameter in Edit mode
BS Correction for Voice Name in Edit mode or command on command line
CTRL + 1 Switch ON/OFF operator 1
CTRL + 2 Switch ON/OFF operator 2
CTRL + 3 Switch ON/OFF operator 3
CTRL + 4 Switch ON/OFF operator 4
CTRL + P Hardcopy of current screen
CTRL + R Replace the data of the currently edited voice by the data saved in the save buffer
CTRL + S Save the data of the currently edited voice in the save buffer
CTRL + STOP Stop loading/saving operation
DEL Up velocity level
ESC Back to previous screen when you are on the Key list screen, stop hardcopy
HOME Down velocity level
INS Normal velocity level
RETURN Enter new value (or name) for parameter in Edit mode, enter command on command line
SELECT followed by a key on music keyboard Change music keyboard split point
SPACE Insert space in Voice Name in Edit mode or in command on command line

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