When the device uses the 40-pin connector, the device receives DC power through a 4-pin connector. The pin assignments are shown in table A.2. Recommended part numbers for the mating connector to 18 AWG cable are shown below, but compatible parts may be used.

	Connector (4 pin)	AMP 1-480424-0 or compatible
	Contacts (loose piece)	AMP 60619-4 or compatible
	Contacts (strip)	AMP 61117-4 or compatible

Figure A.2 - Drive side connector pin numbering

This annex describes a connector alternative often used for 2 1/2 inch or smaller devices. This alternative was developed by the Small Form Factor (SFF) Committee, an industry ad hoc group.

In an effort to broaden the applications for small form factor devices, a group of companies representing system integrators, device suppliers, and component suppliers decided to address the issues involved.

A primary purpose of the SFF Committee was to define the external dimensions of small form factor devices so that products from different vendors could be used in the same mounting configurations.

The restricted area and the mating of devices directly to a motherboard required that the number of connectors be reduced, which caused the assignment of additional pins for power. Power is provided to the devices on the same connector as used for the signals, and addresses are set by the receptacle into which the devices are plugged.

The 50-pin connector that has been widely adopted across industry for SFF devices is a low density 2 mm connector which has no shroud on the plug which is mounted on the device. A number of suppliers provide intermatable components. The following information has been provided to assist users in specifying components used in an implementation.

	Signals Connector Plug	DuPont 86451 or equivalent
	Signals Connector Receptacle	DuPont 86455 or equivalent

1. A.2.1 44-pin signal assignments

The signals assigned for 44-pin applications are described in table A.3. Although there are 50 pins in the plug, a 44-pin mating receptacle may be used(the removal of pins E and F provides room for the wall of the receptacle).

Some devices may utilize pins A, B, C and D for option selection via physical jumpers. Such implementations may require use of the 44-pin receptacle.

The first four pins of the connector plug located on the device shall not to be connected to the host, as they are reserved for manufacturer's use. Pins E, F and 20 are keys, and are removed. See figure A.3.

This subclause defines the pinouts used for the 68-pin alternative connector for the AT Attachment Interface. This connector is the same as the one defined by PCMCIA. This subclause defines a pinout alternative that allows a device to function as an AT Attachment Interface compliant device, while also allowing the device to be compliant with PC Card ATA mode defined by PCMCIA. The signal protocol allows the device to identify the host interface as being 68-pin ATA or PC Card ATA.

To simplify the implementation of dual-interface devices, the 68-pin AT Attachment Interface maintains commonality with as many PC Card ATA signals as possible, while supporting full command and signal compliance with the ATA standard.

The 68-pin ATA pinout shall not cause damage or loss of data if a PCMCIA card is accidentally plugged into a host slot supporting this interface. The inversion of the reset signal between the ATA and PCMCIA interfaces prevents loss of data if the device is unable to reconfigure itself to the appropriate host interface.