When OS/360 was finally released, a year late, it required at least 64 KB of memory. DOS was designed to use little memory, and could run on 16 KB machines, a configuration available on the low-end S/360 model 30. Unlike OS/360, DOS/360 was initially a single-job system which did not support multitasking. A version with multitasking, supporting up to three memory partitions, requiring 32 KB of memory was later released. Despite its limitations, DOS/360 became the most widely used operating system for processors with less than 256 KB of memory because: System/360 hardware sold very well; DOS/360 ran well on System/360 processors which medium-sized organizations could afford; and it was better than the "operating systems" these customers had before.