
Serial and Parallel ATA Drive Guidelines and Features
4.4.2 PATA Power Cable
Pin | Usage |
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1 | +12 V |
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2 | Ground |
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3 | Ground |
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4 | +5 V |
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4.5 PATA Drive Installation Guidelines
The computer system boards for these products have one Parallel ATA (PATA) channel with a single connector. The channel can have up to two devices attached to it. All drives are connected to the channel using an
✎The
Each drive attached to a channel must have a drive designation. If a drive is attached to the Device 0 cable position and its
For optimal performance of a computer system, all drives need to be attached to the PATA channel(s) in a specified sequence. This sequence is determined by the device class of the drives and by specific attach sequence rules.
4.5.1 PATA Device Classes
In order to determine the best drive attach sequence, ATA/ATAPI drives are segregated into four different classes based upon the bandwidth demands they place on an ATA channel. The most demanding devices are in Class 1 and the least demanding are in Class 4.
Class 1 | Class 2 | Class 3 | Class 4 |
Hard | High Speed | Optical Storage | Magnetic |
Drives | Optical Drives | Drives | Storage Drives |
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Supported | DVD | R/W | Zip |
only on USDT |
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chassis with |
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MultiBay |
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General Attach Guidelines
■The lower the device class number, the faster the device and the more bandwidth required.
■Drives installed in the Device 0 position receive the greatest possible bandwidth.
■The bootable ATA hard drive should always be installed in the Device 0 position.
Service Reference Guide, dc7600 |