A homogeneous record of optical photoelectric photometric measurements of this special object is presented, including over 800 observations on about 700 dates during 1979-1985, in the V band. A complete data table is furnished, which can be used for various future analyses and for correlation with other data (radio, X-ray, etc.) The paper presents: (1) a power spectrum identifying the dominant periodicities, 13.081 and 162.5 d; (2) updated ephemerides for these periods; and (3) a mean, binned light curve on the 13 day period. Also, an interesting new synthesis of the average 162 day 'precession' light curves broken down into four phase intervals on the 13 day cycle is shown. A positive 'hump' at the 162 d light minimum is now clearly seen to occur around orbital phase 0.5 (secondary 13 d light minimum) but not at phase 0.0 (primary minimum). The connection with current models is discussed qualitatively.