History (1988): KDD in MO Medium Disk Substrate

KDD in MO Medium Disk Substrate

KDD Research & Development Laboratories (Tokyo, Japan) announced it was working on a magneto-optical disk, which specifications can be found below.

KDD plans an extra special use: a digital still video file system. After the color video signals of NTSC are changed to digital codes by A/D converter and are stored in a frame memory, these codes are recorded on the magneto-optical disk by one frame. 2,300 pictures can be recorded on 30cm disk per side. Time recording/reading pictures will be 2s per picture (one picture is about 400KB.)

KDD’s magneto-optical disk

• Recording Medium: TbFeCo
• Disk Substrate: PMMA (Polymethyl-methacrylate)
• Outer Diameter of Disk: 300mm
• Inner Diameter of Recording Area: 140mm
• Outer Diameter of Recording Area: 285mm
• Track Pitch: l.6μm
• Number of Tracks: 43,750 tracks/side
• Number of Sectors: 20/track
• Sector Capacity: 1,024B/sector
• Effective Total Capacity: 0.9GB/side (corresponds to about 2,300 color still pictures)

KDD’s magneto-optical disk drive

• Disk Rotation: 900rpm
• Mean Access Time: less than 120ms
• Modulation: ETM (eight to ten modulations)
• Data Transfer Rate: 300KB/s
• Error Correction: CIRC (Cross Interleave Reed-Solomon Code)
• Error Rate after Correction: less than 10¹²

This article is an abstract of news published on the former paper version of Computer Data Storage Newsletter on issue ≠2, volume ≠1, published on March 1988.