Honda made smaller displacement (400 and 450 cc) automatics from 1978 to 1983.
http://en.wikipedia.org/wiki/HondamaticThe 400s were made from 1978 through 1981, with the 450s made the last two years. The style for the earlier bikes differed - with the latter years being more of a "custom" of that era.
The engines, other than the displacement, remained mostly unchanged through the production run. One of the nice things is that these bikes do not have any clutch packs to ever wear out (unlike the 76 to 78 750 autos).
I bought an 82 450 for my son - no problems with it.
Suzuki also made a 450 auto, which has reportedly more pep that the Honda version.