The first hard drive, from 1956, was housed in a computer the size of two refrigerators. But in less than a quarter of the century, engineers shrunk hard drives to 5.25". The first, holding 5MB, was Seagate's ST-506.
In 1980, manufacturers were still dedicating significant resources to pushing the upper limits of data storage in colossal machines. In that year, IBM made the first gigabyte hard drive, which weighed over 500 pounds.
But Seagate, a new company, was looking in a different direction, and as their first product they introduced the ST-506, the first 5.25" hard drive. It only held 5MB, a capacity matched even by hulking, decades-old machines, but it sure was small. Small enough that it was used almost universally in the early microcomputers of the day, the progenitors of our PCs.
Seagate soon doubled the 5.25" drive's capacity to 10MB in the ST-412, released the following year, and capacity only continued to grow after that. Eventually, 5.25" drives were discontinued in favor of the smaller 3.5" drives we use today. But the use of 5.25" hard drives continued all the way into 1998, and it's likely that one of your early machines had a drive that used the same form factor Seagate pioneered back in 1980.
Practically every time Apple offers the iPod Nano in a new color, we consider it a new generation of the device, but that might be playing too fast and loose with the term. Tracing the lineage of our drives, from the 5MB 305 RAMAC in 1956, through the 5.25" Seagate ST-506 in 1980 and up to flash storage today gives you a striking sense of how far we've come but makes you appreciate each big breakthrough it took to get here. [Wikipedia and PC Mag]
Memory [Forever] is our week-long consideration of what it really means when our memories, encoded in bits, flow in a million directions, and might truly live forever.