  Results of speckle observations at the 4.1-m SOAR telescope in 2012 (158
measures of 121 systems, 27 non-resolutions) are reported. The aim is to follow
fast orbital motion of recently discovered or neglected close binaries and
sub-systems. Here 8 previously known orbits are defined better, two more are
completely revised, and five orbits are computed for the first time. Using
differential photometry from Hipparcos or speckle and the standard relation
between mass and absolute magnitude, the component's masses and dynamical
parallaxes are estimated for all 15 systems with new or updated orbits. Two
astrometric binaries HIP 54214 and 56245 are resolved here for the first time,
another 8 are measured. We highlight several unresolved pairs that may actually
be single despite multiple historic measures, such as 104 Tau and f Pup AB.
Continued monitoring is needed to understand those enigmatic cases.
