PURPOSE: To restrict complexity of data processing for controlling a printer and restrict an increase in data transfer period, by a method wherein a code conversion table corresponding to the type element mounted are stored in an RAM by a controlling means for rewriting of tables.

CONSTITUTION: When a controlling circuit 7 for the rewriting of the tables is inputted with a control signal TD from a discriminating circuit 2, the circuit 7 starts to control the rewriting of each of the tables 4, 5, 6 for hammer printing pressure, ribbon feed amount and proportional space amount. The hammer printing pressure, the ribbon feed amount and the proportional space amount corresponding to the type indicated by input data DT are stored in the RAM as the code conversion table. After the rewriting is completed, a change-over control is performed so that type position data PDD derived from a wheel position table 3 are inputted from an ROM into the RAM.