4221WD (WIDE, DIFFERENTIAL) CONFIGURATION INFORMATION

For Drive Specifications, click here.

For Dimensions and Mounting Information, click here.

For Electrical Interface, click here.

Configuration and Jumper Options

Pin Numbers refer to the Option Jumper Block)


SCSI ID Selection

Up to sixteen devices (the host and fifteen targets) can be attached to the SCSI bus. These are selected with jumpers on the Option Jumper Block or on Auxiliary Connector J1B (use either but not both); see the Note below the J1B drawing for J1B usage. In multiple-device systems, each device must have its own Unique SCSI ID. The SCSI ID (drive address) jumpers are identified as ID0, ID1, ID2, and ID3. ID selection is binary, as shown below.

 
	SCSI ID		ID3	ID2	ID1	ID0
0 (Default) out out out out 1 out out out in 2 out out in out 3 out out in in 4 out in out out 5 out in out in 6 out in in out 7 out in in in 8 in out out out 9 in out out in 10 in out in out 11 in out in in 12 in in out out 13 in in out in 14 in in in out 15 in in in in


Interface Termination

An external terminator provides termination for the interface lines.

Suggested end-of-cable terminator: Methode DS2050-01-68D


Terminator Power

If a jumper is installed at W1 (Default), the drive provides terminator power (TERMPWR) to the bus.

If the jumper is omitted, the host system provides TERMPWR.


Remote LED

A user-supplied LED may be connected to Remote LED (Pins 1 and 2).


Spindle Options

Jumpers at SP0 (Pins 11 and 12) and SP1 (Pins 13 and 14) control the spindle options.

	SP0	SP1
N N The drive starts the spindle motor at power-on. (Default) Y N The drive waits for a Start Unit SCSI command to start the spindle motor. N Y Spindle start-up is delayed based on SCSI ID address (12 seconds per ID)


Write Protect

A jumper at WP (Pins 15 and 16) selects the write protect option.

	Jumper		The drive is write protected.
	No Jumper	The drive is not write protected. (Default)


Parity

A jumper at PTY (Pins 17 and 18) selects the bus parity check option. The drive always generates parity regardless of this option.

	Jumper		SCSI interface parity checking disabled.
	No Jumper	SCSI interface parity checking on. (Default)


Spindle Sync Signals

Use of the MSYNC and SSYNC signals is optional. These signals are used as spindle synchronization reference.

Auxiliary Connector J1B


Note: J1B is sampled at initialization for jumpers on pins 7-8, 5-6, 3-4, and 1-2 for SCSI ID3, ID2, ID1, and ID0 respectively; these connections (if not jumpered) are then released for the following usages:

A dash character (-) at the end of a signal name indicates that it is asserted at the low level (i.e., active low) and negated at the high level.


Drive Fault (XTFALT-)

Output signal negated (Default); indicates no drive fault.

Output signal asserted; indicates a drive fault condition.


Slave Sync (SSYNC-)

Use is optional; used as spindle synchronization reference.


Remote LED-

Open collector output; used to drive a user-supplied LED to indicate the drive is active.


Ground (GND)

Logic ground; provides signal ground.


+5 Volts (+5V)

5 VDC (1A max); used to drive external LEDs.


Write Protect (FAULT-)

Input signal negated (Default); drive is not write protected.

Input signal asserted; drive is write protected.

Last Update 21 August 1995