8 or 16 kilobytes of RAM was common ; 64 kilobytes was considered a vast amount .
Was the entire address space accessible to the 8 - bit CPUs predominant during the earliest generations of personal computers .
8 or 16 kilobytes of RAM was common ; 64 kilobytes was considered a vast amount and was the entire address space accessible to the 8 - bit CPUs predominant during the earliest generations of personal computers .