Seagate Technology was founded in 1979 by Alan Shugart and Finis Conner; their first product (released in 1980) was the ST-506, the first hard drive to fit the 5.25″ form factor. Through the 1980s, Seagate mainly sold
simple drives that were derivatives of (and improvements upon) the original ST-506 design; the ST-225 20MB drive and ST-251 40 MB drive were the biggest sellers of this age. Capacity of ST-251 is 42.8 MB, speed 3600
rpm..