Quantum Corp has secured a major Soviet order for hard disks, ousting Seagate Technology Inc and MiniScribe Corp to become supplier to Aquarius, one of the larger Soviet personal computer assemblers and systems integrators. From this month the components manufacturer will be the sole supplier of hard disks to the Aquarius assembly plant in Shuya, near Moscow. The factory is currently turning out 3,000 to 4,000 units per month but aims to increase this to 10,000 by the end of 1991. Aquarius is a Soviet-German joint venture, part owned by Aquarius Systems Inc. The Soviet joint venture now has 60 service centres across the USSR. Like Chips & Technologies Inc of the US, Aquarius Systems has chosen assembly rather than export because there are lower Soviet import tariffs on components than on complete systems.