[buescher]

>"Since a base-3 electronic technique is not available, they decided to construct a base-4 machine and to utilize only 3 of the 4 possible states. The unused fourth state in each case is available for some form of checking."

Thanks - that clears some things up. It also appears that DSSP (Soviet trinary Forth, yes there was such a thing), postdates Forth, was based on Forth, and was not an independent discovery as it is sometimes represented. http://www.euroforth.org/ef00/lyakina00.pdf