Ferranti's Sirius was a small computer released in 1961 (operating in 1959 on a time rental basis). Designed to be used in smaller offices without a dedicated programming staff, the Sirius used decimal arithmetic instead of binary, supported Autocode to ease programming, was designed to fit behind a standard office desk, and ran on UK standard mains electricity (then 240 V) with no need for cooling. It was also fairly slow, with instruction speeds around 4,000 operations per second, and had limited main memory based on delay lines, but as Ferranti pointed out, its price/performance ratio was difficult to beat.