Patent US 3,958,227

A branch-address translation register (BAXR) is loaded by a current or a prior control word field. A word selection decoder circuit receives the BAXR outputs and combines them with machine-status signals to generate a word selection signal for selecting a control word from a currently accessed branch group in the control store. A BAXR switching circuit is also provided so that any control word can switch off the BAXR output and cause a control word selection without translation. The invention can obtain any required degree of addressing flexibility in microcode branch selection, i.e. from partial to total flexibility.