 Also in 1973, Control Data Corporation introduced the first of its series of SMD disk drives using conventional disk pack technology.The SMD family became the predominant disk drive in the minicomputer market into the 1980s.Smaller diameter media came into usage during the 1970s and by the end of the decade standard form factors had been established for drives using nominally 8-inch media (e.g., Shugart SA1000) and nominally 5.25-inch media (e.g., Seagate ST-506).