128-bit computingGeneral home computing and gaming utility emerge at 8-bit (but not at 1-bit or 4-bit) word sizes, as 28=256 words become possible. Thus, early 8-bit CPUs (TRS 80, 6502, Intel 8088 introduced 1976-1981 by Commodore, Tandy Corporation, Apple and IBM) inaugurated the era of personal computing. Many 16-bit CPUs already existed in the mid-1970's. Over the next 30 years, the shift to 16-bit, 32-bit and 64-bit computing allowed, respectively, 216=65,536 unique words, 232=4,294,967,296 unique words and 264=18,446,744,073,709,551,615 unique words respectively, each step offering a meaningful advantage until 64 bits was reached.