Uploaded on Jan 15, 2015 Korg
"The new MS-20m and SQ-1 open a whole world of analog experimentation. Connect, sync, and sequence all your gear with the flexible SQ-1 Step Sequencer, and take the famous MS-20 sound to new levels with the FM and sync features of the tabletop MS-20m"
Note the SQ-1 comes included with the MS-20m kit. The MS-20m has a selectable filter switch on the front panel while the original MS-20 kit had to be set internally. There are number of additional improvements outlined directly below. [Details on the SQ-1 just
posted here]. Fun little bit of trivia is you can see SN 000001 on the back image below. Often there is no serial number in promo shots. Thought it was kind of neat and adds to the history of whomever this particular unit ends up with. Also note it's lower case "m".

First, the enhancements over the original:

"Carrying on the distinctive synthesis of the MS-20, the MS-20M features additional improvements in both looks and functionality. Extending to detailed aspects of the design, the sound-creating possibilities have been dramatically boosted, making this sound module even more attractive and raising it to an even higher state of completion.

SYNC ON/OFF switch allows oscillator sync
Oscillator sync forcibly synchronizes the phase of VCO1 to the phase of VCO2, producing a powerful sound with complex overtones.

FM ON/OFF switch allows frequency modulation
The VCO1 waveform can be used to frequency-modulate the VCO2 waveform (FM or cross modulation), creating vibrato effects or extreme metallic sounds.

FILTER TYPE switch lets you select two types of filter
The original MS-20 used two different VCF circuits depending on the date of production, and now you can choose either of these with a single switch. The earlier model (REV.1) has an aggressive character with distinctive distortion and self-oscillation, while the later model (REV.2) has minimal noise and a sweet, mellow sound.

PWM IN jack allows pulse width modulation
The PWM provided on the MS-10 of the past is now possible on the MS-20. By cyclically modulating the pulse width of the VCO1 square wave, you can obtain a distinctively fat sound.
EG2 NORMAL OUT jack expands your sound-creating potential
In addition to the previous EG2 REV OUT, we've provided a normal EG2 OUT that varies in the range of 0V--+5V.
TRIG SW button lets you conveniently audition the sound
Even on this keyboardless unit, the trigger switch lets you smoothly audition the sound while you edit the parameters.
Numerous jacks have been added to the MS-20M, letting you connect it with any type of device.
All CV/GATE specifications are supported: Hz/V and V/Oct, S-Trig and V-Trig
From the time when it was originally produced, the CV standard used by the MS-20 was not the commonly used V/Oct standard, but rather the Hz/V standard that provided superior pitch stability. However, like the MS-50 of that time, the MS-20M Kit provides CV IN jacks for both the Hz/V standard and the V/Oct standard.
For the TRIG IN jack that receives gate signals, jacks are provided not only for the S-Trig standard as on the original MS-20, but also for the widely used V-Trig standard. The MS-20M Kit supports any sequencer or controller that's equipped with CV/GATE output.
Three JUNCTION jacks
Three sets of the junction jacks once provided by the MS-50 are also provided. Output signals from the SQ-1 step sequencer or similar device can be converted from a mini-phone plug to a 1/4" phone plug, or those signals can be distributed to multiple destinations for a variety of possibilities.
MIDI IN connector and USB connector
There's a MIDI IN connector that can receive note messages, and a USB-MIDI connector that can transmit and receive note messages. You can perform using a taktile or other MIDI keyboard, or perform sequences that you've recorded on your DAW.
And the general description for the archives:
"The evolution of the MS-20, delivering even more powerful synthesis.
A module that you assemble, with a step sequencer included.
The classic MS-20 analog synthesizer that appeared in 1978 has been reborn as a perfect reproduction of the original circuit, first in 2013 as the mini-sized MS-20 mini, and now in 2014 as the MS-20 Kit that you can assemble yourself.
The MS-20 Mini and the Kit were designed by the engineers who developed the original MS-20. At its introduction, the designers of the MS-20 wanted to create an interesting product quickly; the result was an enormous hit, but the designers felt there were actually a few things left undone. Now, after 37 years, the user-assembled MS-20M Kit has been completed.