Family Alias : AL3

Terminal CN4
ID2	ID1	ID0	SCSI ID
OPEN	OPEN	OPEN	0
OPEN	OPEN	SHORT	1
OPEN	SHORT	OPEN	2
OPEN	SHORT	SHORT	3
SHORT	OPEN	OPEN	4
SHORT	OPEN	SHORT	5
SHORT	SHORT	OPEN	6
SHORT*	SHORT*	SHORT*	7 (Default)
Pins 2, 4, and 6 which are closest to the PCA carry the GND signal

Terminal CN6 (Model SA, SY only)
Function	Label	Pins	Result	Comments
Spindle motor control	A	SHORT*	Auto start on power up	-
		OPEN	Controlled by START/STOP unit command
SCSI Bus parity check	P	SHORT*	Enabled	-
		OPEN	Disabled
Offline diagnostics	D	SHORT	Enabled	-
		OPEN*	Disabled

Terminal CN7
Function	Label	Pins	Result	Comments
Spindle Sync I/O pulse	SY	1	GROUND	-
			SPSYNC
External Reset	R	SHORT	Reset	-
		OPEN*	Normal operation
Write Protection	W	SHORT	Enabled
		OPEN*	Disabled
SCSI bus termination	TM	SHORT*	Enabled
		OPEN	Disabled (normal operation)

Switch & Jumper Settings

Terminal CN6 (Model E only)
Function	Label	Pins	Result
Unused	A	SHORT*	Unused
		OPEN
	P	SHORT	Connection of SCSI terminating resistor on SCSI bus for 8-bit SCSI (when DB07 to DB15 and DBP1 signals are not used)
		OPEN*
Offline diagnostics	D	SHORT	Offline diagnostics enabled
		OPEN*	Normal operation

Orientation

The drive may be installed in one of five orientations; either PCA down or on any edge. Inclination from vertical or horizontal should not exceed 5°.

Mounting Screw Fixing

When the mounting screw holes on the side of the drive are used, then use only the two pairs of outer holes. Do not use the centre holes in conjunction with only one of the outer holes. Drives with the suffix "M" accept M3 screws while drives with the suffix "U" accept #6-32UNC screws. The screw must not penetrate the drive by more than 4 millimetres

Grounding

Magneto-Resistive Read heads are a significant factor in the achievement of very high capacities in small form factor hard disk drives. These drives use Magneto-Resistive (MR) heads and therefore require special handling considerations. The MR head must be electrically biased in order to function, and Fujitsu use +5.5VDC on these drives. The voltage is generated by the drive electronics from the normal +5VDC and +12VDC rails, so standard power supplies and connectors may be used.

With the MR head biased in this way, it becomes important to avoid the possibility of discharge between the head and the media, so, in order to ensure operational reliability, the disk enclosure (DE) and hence the platters themselves are also biased to +5.5VDC resulting in zero potential difference between head and platter. This means that the outer casing of the DE is set at +5.5VDC rather than DC Ground as would be the case on a conventional drive.

Users must ensure that the DE casing is NEVER shorted to the computer system's Frame or DC Ground.

Fujitsu have taken steps to minimise the possibility of accidental shorting by coating the DE with an electrically insulating material and by removing the earthing tag that would normally be present. Also the drive is protected against damage in the event of accidental shorting through the use of a protection circuit in the head IC. This works by quickly shutting off the bias voltage when it detects a voltage drop. Any read or write operation during this time will result in a hard data error. When the short is removed the bias voltage is automatically restored and read/write operations will again work normally. Pay close attention to the mounting specifications of the drive ensuring that no component of the system is likely to abrade the disk enclosure surface.

Cooling

Allow space above and below the drive to provide for adequate air flow. A 2.5 millimetre gap around the drive is recommended. Fan cooling is also recommended. The disk enclosure temperature, measured at top centre, should never exceed 55°C.

This is a high performance disk drive and in order to ensure reliablity and optimum performance it must be kept cool at all times. Always use a high quality enclosure that incorporates adequate forced air cooling (i.e. an electric fan) that will keep the temperature of the disk enclosure surface to less than 55°C. Check after about three hours of typical operation that this specification has not been exceeded.