IBM introduced the world’s first commercial storage system, the 305 RAMAC. in 1956. A magnetic disk was used to store data and was intended for a secondary storage system. RAMAC stands for Random Access Method of Accounting and Control and was designed for real-world needs of accounting in business. The first customers was the US Navy.
This physical size of the 305 was 6′ wide by 5′ deep (feet). Total storage capacity was 4.4MBs (megabytes). The weight for this storage system was just over one ton (source).
Today, (2022) we can see a 1TB (terabyte) of storage in a microSD card (TF Card) at the small size of 15mm x 11mm and the weight is under one gram.
The big selling point from IBM in 1956 was the ability for the 305 to store the equivalent of 64,000 punch cards on its magnetic disks. Punch cars are stiff pieces of paper which contain digital data represented by the presence [or absence] of holes in predefined positions on the card.
The IBM 350 disk system could store 5 million alphanumeric characters as six data bits, one parity bit, and one space bit, for a total of eight bits per character. It had fifty disks with a diameter of 24 inches. Under servo control, two independent access arms moved up and down to select a disk and in and out to select a recording track.
In comparison, today’s 1TB microSD card will hold about 6.5 million documents and said another way, 6.5 million documents bit in about 1,300 filing cabinets. The seek time to find a single file is about
In 1957, IBM would lease the RAMAC 305 for about $3,200 per month (roughly $33,000 in 2022 dollars). Over one thousand 305 systems were manufactured before production ceased in 1961.
Digital Storage in the Future
If we consider Moore’s Law which is storage capacity and technology in general will double every 18 months, we can calculate 43 cycles of Moore’s Law between today and 65 years into the future. Doing some advanced math, we figure the storage capacity of a microSD card, if still available, in 2087 will be 18,446,744,073,709,600,000,000,000 TBs of data.