Patent US 4,093,922

A television tuning system having a non-volatile memory for storing digital tune words is electrically updated by a microcomputer type architecture control circuitry. A ROM memory matrix is provided for the storage of VHF minimum and maximum binary tune words corresponding to each of twelve VHF channels in addition to a UHF minimum and maximum binary tune word encompassing all possible 72 UHF channels. Tuning of individual VHf and UHF channels is accomplished by incrementing or decrementing a given tune word within the minimum and maximum limits established in the ROM memory matrix by means of a microcomputer processing approach.