via this listing
Pics of the inside below.

The new MS6 firmware is version 1.3, based on the V9.0 Cheetah ROM, has the following extra features:
MIDI bank select (CC #0), globally and per-part.
Program change per-part.
Remote control of all tone edit parameters using CC messages, both in tone and performance mode.
No more partial drop-outs at bottom C (130.8Hz).
Three more DCO shape settings, both for DCO A and B: off, pulse + triangle and pulse + sawtooth. The new pulse shapes can use PWM as well.
Extended SysEx support: single patch and edit buffer dumps + requests, full dump and status requests.
Mono mode, per-part, with a choice of always retriggering the envelopes or to not retrigger when playing legato (i.e. pressing a new key before releasing the current one).
Portamento, per-part, constant-time (0.015 - 18.3 s) or constant-rate (400 - 0.44 semitones/s). Full-time or fingered (i.e., only in mono mode when playing legato).
Support for bank 7 tones in performances."