Thomas R. Grant

Tom's Disk, an Amiga Animation by Thomas R. Grant

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Tom's Disk

Renderd disk in Real 3D. Took about 6 hrs to do.

(Thomas R. Grant)

This is a rather unusual animation of a 3.5-inch DD disk where the disk, a thin, flexible 'floppy' magnetic storage medium and its plastic shell are rotating in opposite directions. The Commodore Amiga computers used an 880 kByte format (11 * 512-byte sectors per track) on a 3.5-inch floppy. Because the entire track is written at once, inter-sector gaps could be eliminated, saving space. The Amiga floppy controller was basic but much more flexible than the one on the PC who only used an 720 kByte format on the exact same medium: it was free of arbitrary format restrictions, encoding such as MFM (Modified Frequency Modulation) and GCR (Group Code Recording) could be done in software, and developers were able to create their own proprietary disc formats. Because of this, foreign formats such as the IBM PC-compatible could be handled with ease (by use of CrossDOS, which was included with later versions of AmigaOS). With the correct filesystem driver, an Amiga could theoretically read any arbitrary format on the 3.5-inch floppy, including those recorded at a slightly different rotation rate. On the PC, however, there is no way to read an Amiga disk without special hardware, such as a 'CatWeasel', or a second floppy drive, which is also a crucial reason for an emulator being technically unable to access real Amiga disks inserted in a standard PC floppy disk drive.

© Walter Randelshofer. All rights reserved. Animations used under permission.