Extract from this brochure:

The B 6800s are directly object-code compatible with the B 6700, B 7700 and B 7800 systems. Users can move through the full range of these computers, a power range from 1 to 50 without reprogramming or recompiling.

Burroughs B 6800 systems are programmed exclusively in high-level languages, increasing programmer productivity, and reducing application development and maintenance costs.