 In April 1953 the State commission accepted the BESM-1 as operational, but it did not go into series production because of opposition from the Ministry of Machine and Instrument Building, which had developed its own weaker and less reliable machine.Lebedev then began development of a new, more powerful computer, the M-20, the number denoting its expected processing speed of twenty thousand operations per second.In 1958 the machine was accepted as operational and put into series production.