Five and quarter drives

From: Eric Smith <>
Date: Fri Feb 11 18:30:49 2005

Dwight wrote:
> Also, not mentioned is that I believe the rotation
> rate is different for the two drive. (360/300 rpm or something)

There are two kinds of 1.2M (HD) 5.25-inch drives:

1) Some drives use a pin on the bus to signal which motor speed
    (300 or 360 RPM) to use, so that a host can handle DD and HD disks at
    the normal 250 Kbps and 500 Kbps data rates.

2) More commonly, the drive does a fixed 360 RPM, which means that HD
    disks use a 500 Kbps data rate, but DD uses 300 Kbps (rather than the
    normal 250 Kbps at 300 RPM).

Received on Fri Feb 11 2005 - 18:30:49 GMT

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