This machine belongs to the most advanced fully-automatic Madas, the “B” models, like 20BG, 20BVG, 20BS, 20BZS, 20BTG and 20BTZG. It allows fully automatic positive or negative multiplication and fully automatic division with variable or constant factors. Instantaneous automatic transfer of products (a*b*c), also for raising any number to any power. This model is very close to the 20BVG model.
Just like any other model, without a “Z” feature, the Product Register has a tens carry-over to two places beyond the keyboard capacity.
Among characteristics, there is a lever for disengaging automatic carriage return after multiplication, to facilitate following this immediately with division. It is also possible to have a “split clearance” in product register, enabling individual and accumulated products to be shown at the same time.
By turning the lever over dial 9, automatic clearance can be disconnected from the 8th to the 20th dial in the “Product Register”. If this is done, dials 1-7 will clear themselves, whilst dials 8 to 20 will accumulate in multiplication.
This model is an evolution of the 20AG and it has an odd characteristic. This is the only machine, among the “B” models, which has no dividend-setup key. It requires the setting of figures by the small knobs above the Register I, after moving manually the carriage to the extreme right.