Last Known Ensoniq O.S. Versions

EPS 2.49/2.40
EPS/M 2.49/2.41
EPS16+ 1.3/1.00F
MASOS 2.0
MIRAGE 3.2
ESQ(1) 3.5
ESQ-M* 1.2*
SQ-80 1.8
VFX 2.30
VFX-SD 2.1/2.00
SQ-1 1.11
SQ-1 32 2.03
SQ-1+ 1.15
SQ-R 1.2
SQ-R 32 2.03
SQ-R+ 1.15
SQ-2 1.2
SQ-2 32 2.03
SD-1 4.10/4.10
SD-1 32 4.10/4.10
DP/4 1.15
DP/4+ 2.02
KS-32 3.10
ASR-10 3.53/1.15
ASR-88 3.53/3.50
KMX-8 2.00
KMX-16 1.50
TS10/12 3.05
KT-76/88 1.62
Soundscape 1.3.03

*
"We believe that 1.2 is the latest ESQm OS.
The latest working OS revision we have is 1.1.
If you find 1.2 someplace on the Internet (as of September 2008),
it is probably a corrupted ROM dump and will not work in your machine. 
If you have access to 1.2 please contact us about uploading your ROM."