Browse Prior Art Database

Low Cost Three-Mode Floppy Disk Drive Support Method

IP.com Disclosure Number: IPCOM000117404D
Original Publication Date: 1996-Feb-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Ioki, K: AUTHOR [+2]

Abstract

Disclosed is a low cost three-mode Floppy Disk Drive (FDD) support method. The current IBM* compatible personal computers in Japan are using the three-mode floppy disk drive to support both 1.44M and 1.2M format 3.5 inch diskette. This method supports new data rate by the floppy disk controller on the personal computer mother board so that both types of these diskettes can be accessed by the normal two-mode floppy disk drive.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 83% of the total text.

Low Cost Three-Mode Floppy Disk Drive Support Method

      Disclosed is a low cost three-mode Floppy Disk Drive (FDD)
support method.  The current IBM* compatible personal computers in
Japan are using the three-mode floppy disk drive to support both
1.44M and 1.2M format 3.5 inch diskette.  This method supports new
data rate by the floppy disk controller on the personal computer
mother board so that both types of these diskettes can be accessed by
the normal two-mode floppy disk drive.

      There mainly exist two types of 3.5 inch diskette format for
the personal computer in Japan.  One is 1.44M byte format which is
formatted by the 300rpm floppy disk drive at 500Kbps data rate.  The
other is 1.2M byte format which is formatted by the 360rpm floppy
disk drive at 500Kbps data rate.  In order to read or write both of
these two types of diskette, the three-mode floppy disk drive is
currently used.  The three-mode floppy disk drive supports both
300rpm and 360rpm motor speed, but is more expensive than the normal
two-mode floppy disk drive which only supports 300rpm motor speed.

      This new method supports 417Kbps data rate by the floppy disk
controller.  The floppy disk controller chip is implemented on the
personal computer mother board and supporting this new data rate does
not increase the chip cost.  At this 417Kbps data rate, 1.2M byte
format diskette can be read and written by the 300rpm floppy disk
drive.  Of course, 1.44M byte format diskette...