History (1989): 4-20MB Floppy Disks by Mitsubishi Chemical Industries

Mitsublshi Chemical Industries has developed 3.5-inch FDs using a barium ferirte and metal magnetic materials that provide 4-20MB storage capacity.

Rather than the conventional gamma iron oxide or cobalt added gamma iron oxide coatings, the barium ferrite material features a particle size of 0.5μm. It has a maximum coercive force of 700Oe and magnetic saturation of 400G.

The metal disk coating particles measure 0.2MUm in length, have a coercive force of 1,500Oe and magnetic saturation of 2,100G.

The surface has a roughness of 0.01μm half that of existing products.

No plans have been made yet for sample release or mass production of disks using this new coating material.

This article is an abstract of news published on the former paper version of Computer Data Storage Newsletter on issue ≠14, volume ≠2, published on March 1989.