North Korea secretly purchase missiles required precision machinery and components from a surprising importing countries and regions : hydraulic and other precision metal machinery from Taiwan companies to import; computer machine from the Swiss company ; several tons of special steels from company in China; from Japan to buy precision machine.
after the disintegration of Soviet Union, 190 missile experts went to North Korea.
1969, North Korea first got two "Scud B missile" from Egypt, North Korea demonstrated to Hwasong-1 missele, and improved to 2-6, in the Iran-Iraq war, Iran purchased Hwasong-3/4(Scud B) from North Korea
Iran's money and North Korea tech made RO-DONG-1 missile in 1991,
North Korea got Russian SS-21 missile from Middle East Countries by communication in middle 90s , and demonstrated to KN-02
North Korea also got SS-N-6 from Russia ,In the late nineteen eighties, Soviet leader Gorbachev and Secretary of defense Yazov's consent, Makayefu design bureau chief designer Igor Villec branch introduced North Korea Machinery Industry Minister Pu Songfeng (deceased) recommend R-27 submarine-launched missiles, and is willing to transfer the technology , this is believed to be the later "dance of water" missile project the source.In 1991, on the eve of the Soviet collapse, has more than 160 Soviet experts stationed in Pyongyang 125 factory, Minsk automobile factory production 6 MAZ-547 vehicles sold to North Korea, for its imitation
The disintegration of the Soviet Union, made more country got missile tech and experts.