Triple density floppy, anyone? \ VOGONS

Everybody knows about 3.5 inch HD 1.44MB floppies, first introduced in 1985 by NEC inside PC-8801 mkII MR(MR was afaik first computer with HD floppy, but 5.25 1.2MB one). West first heard about them from 10 November 1986 InfoWorld "Vendor Introduces Ultra High-Density Floppy Disk Media" https://books.google.com/books?id=rDwEAAAAMBAJ&pg=PA19 IBM followed in 1997 switching PS/2 to 2HD floppies, Apple in 1988. 80 tracks ~50KB/s speed.

But pretty much nobody outside of Japan has ever hear about 'Triple' or '2TD' format developed and shipped by NEC inside PC-88 VA3 in 1988. 13MB unformatted, 9MB formatted capacity!! Triple because it tripled track density from 80 to 240 while reusing ED barium ferrite magnetic media, same ~100KB/s speed.

The best (only) document describing this format is NEC uPD72070 floppy controller documentation, curiously stored under apple/sony at bitsavers http://bitsavers.informatik.uni-stuttgart.de/ … cation_1991.pdf Simplicity of the design suggests any ED capable (1Mbit bitrate) controller should work out of the box with Triple floppy drive.

AT&T Globalyst/FIC 486-GAC-2 Cache Module reproduction Zenith Data Systems (ZDS) ZBIOS 'MFM-300 Monitor' reverse engineering

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