Five and quarter drives

Randy McLaughlin randy at s100-manuals.com
Fri Feb 11 18:47:43 CST 2005


From: "Eric Smith" <eric at brouhaha.com>
Sent: Friday, February 11, 2005 6:30 PM
> 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).
>
> Eric

When the PC-AT first came out there were two different types of 1.2M drives:

360RPM using 600K transfer rate & 300RPM using 500K transfer rate.

Gets confusing doesn't it?


Randy
www.s100-manuals.com 





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