I have a Bikron Binary Chronometer that appears to function well (after replacing four burned out light bulbs), but I do not have an owner's manual or instructions. FRONT COVER OFF Removing the plexiglass cover reveals the bulbs and a pair of switches, which are used to set the clock. The bulbs are GE/Sylvania type 53, which are the bayonet style (push and twist to insert or remove). The display is organized into five columns. The two right-most columns represent seconds; the right-most column is the ones-position and the column to its left is the tens-position. The right-most column counts the seconds from zero to nine in binary (least significant bit at the top) while the column to its left counts the tens-of-seconds from zero to five. The next two columns represent minutes in a manner identical to the seconds. The center column is the ones-position and the column to its left is the tens-position. The center column counts the minutes from zero to nine in binary (least significant bit at the top) while the column to its left counts the tens-of-minutes from zero to five. The left-most column is the hours, which counts from zero to eleven in binary. SWITCHES LEFT SWITCH The left switch allows setting the minutes and hours. Pushing this switch to the far right advances the minutes along at the rate of one minute per second. Pushing this switch to the far left advances the hours along at the rate of one hour per second. The center position is the normal (not setting) position. RIGHT SWITCH The right switch controls the run/hold operation. Pushing the switch up allows the clock to run normally. Pushing the switch down places the clock in "hold" mode where timekeeping is frozen, allowing manual synchronization to an external time source (sometimes called a "hack").