Latest BEAM spec?

[James Hague]

I've been looking at the BEAM emulator source code and a BEAM
specification document (the latter is from October 1997, version 1.2).  It
seems that only a subset of the BEAM instruction set is actually
implemented in the current system.  True?  Were the other instructions
simply not implemented or have they been removed from the BEAM spec?  Is a
more recent spec publicly available? 

James