In parallel to participating in CEH Beta21 project (see our prior blog article here) Omega pushed its own efforts to create quartz movements -- and in different directions. Basically there are just two horological relevant targets for a quartz movement: miniaturization & precision.
To achieve the end-point in precision, Omega worked on its MegaQuartz caliber 1500 -- a quartz movement that worked at a rate of 2.4 MHz and thus more than 70 times the rate of a standard quartz watch. Omega started this project in the late 1960s already and was able to present an early prototype (named 'Elephant', 2nd from left) on Basle fair April 1970, when Beta21 was released and marketed as well. However, the movement housed in the 'Elephant'-case is far from being production ready and things in there work even today but are hand-soldered.
Please note the correspondence of the case design of this prototype to the first Omega Beta21 'Pupitre' -- 1970, unmistakable. And notably both have their setting crown on the left side of the case to demonstrate: you simply dont need it.
The last pre-production prototype is the one 2nd from right and was created in 1972 just months before the introduction of this movement as cal1510. And the introduction was a big bang in a heavy gold case with lavish aventurine dial -- shown on the right. The 2.4MHz MegaQuartz Endboss and the most precise quartz watch for years.
Later in the 1970s the product line was extended by cal1511 & cal1516 and different lower priced steel variants -- but that were just minor tweaks here and there, country-specific and import-restriction driven changes and reactions to changes in 3rd party supplied parts. The relevant part of the story was already told with arrival of the gold cased Aventurine dial MegaQuartz cal1510.
It is said that close to 6'000 examples were made in all variants of cal1500 and just 200 in yellow gold, housing a cal1510. A further 800 in steel holding cal1510 as well. And the remaining 5'000 were made of steel & steel / gold (bicolor) with the minor enhanced calibers 1511 & 1516 -- please see the in depth research on the horological legend Omega MegaQuartz by @t_solo_t here.