History (1989): 3.5-Inch Erasable Optical Drives Based On Phase-Change From Matsushita

Up to now, all erasable digital optical discs were based on magneto-optical technology. But now the phase-change technology is arriving.

The first company involved in it seems to be Matsushita Electric Industrial Co. that introduced a 3.5-inch drive in phase-change technology developed by Energy Conversion Devices, Inc. (Troy, MI).

The thin film coating the disc is heated to alter its crystalline structure by a laser power. The beam can read out data at low power, and a direct overwrite system erases data.

This article is an abstract of news published on the former paper version of Computer Data Storage Newsletter on issue ≠15, published on April 1989.