The idea of a Mesoamerican abacus has been explored by David Esparza Hidalgo  initially and then by others . The interested reader can study it further in the references. This page provides a simulator for such a device.
Operate the abacus by clicking the mouse-pointer on the beads.
As the user can see, this is similar to a Chinese abacus, (and in fact, the source has been generalized from the Abacus java class), except that the dimensions are strictly 7 rows by 13 columns, important numbers in Mesoamerican beliefs.