I'm *guessing* the tms0260 is the immediate predecessor of the speak and spell MCU which is tmc0270 (well, ti numbered the first few masks of each chip by incrementing the last digit i.e. tmc0271 tmc0272, tmc0274 etc, though later chips are tmc0270-xyz)
"When life gives you zombies... *CHA-CHIK!* ...you make zombie-ade!"