[DECtalk] question about DECtalk versions

[Mohamed]

HI guys, I was wondering something. Is there a changelog somewhere which 
actually lists what changes were made in versions of DECtalk? I realize 
that dectalk was originally a hardware synth so logs of earliest release 
notes back then would be hard to find but what about the software 
versions? Has anyone found release notes for what was changed in those 
versions anywhere?
Thanks.