A SCSI bus cable, power cable, and frame ground cable are required to operate the drive. If two or more SCSI devices are connected to the same SCSI bus cable, SCSI address setting and terminating resistor ON/OFF switches must be altered properly. The drive has some optional function setting by switches to be set depending on the desired operating. NEC Global Portal Site. Support & Downloads Get troubleshooting, maintenance and warranty information.
Layout
NEC D3861 PRODUCT DESCRIPTION 806-520918-0 REV. A 1989
Jumpers
NEC D3861 PRODUCT DESCRIPTION 806-520918-0 REV. A 1989
Jumper Setting
SCSI Address Setting
--------------------
The SCSI address is factory-set to '0'. If two or more SCSI devices
are connected to the same SCSI bus, alter the SCSI address with the
switch shown in the following figure.
Optional Function Setting
-------------------------
This magnetic disk drive is provided with optional functions that can
specify use or non-use of a Start/Stop Unit command, one of the SCSI
commands, and ON/OFF of SCSI BUS parity check. This function is
factory set so that the spindle motor starts regardless of a Start/
Stop Unit command and the parity check is set to ON automatically
when the power is turned on. To start the spindle motors of two or
more drivers sequentially with a Start/Stop Unit command, alter the
switch setting beforehand as shown in following figure.
SCSI Address Option Function Setting
------------------------------------
Setting of Use or Non-use of a Start/Stop Unit Command and ON/OFF of
SCSI Parity Check.
NOTE
Setting of the SCSI ADDRESS switch is read during resetting or when
power is turned on.
NOTE
Setting of the AUTO MOTOR START and PARITY CHECK ON/OFF switches
becomes valid immediately after setting.
Install
NEC D3861 PRODUCT DESCRIPTION 806-520918-0 REV. A 1989
Notes On Installation
The D3861 magnetic disk drive can be installed both horizontally and
vertically. When installing the drive horizontally, be sure to
install it with the main pronted wiring assembly faced down. (Do NOT
face the front panel upward or downward.)
The drive has eight mounting tap holes.
An SCSI bus cable and power cable are required to operate the drive.
If two or more SCSI devices are connected to the same SCSI bus cable,
SCSI address setting and terminating resistor ON/OFF switch must be
altered properly. The drive has a switch for accepting or rejecting
and Auto Motor Start at power on and that for setting of ON/OFF of
SCSI BUS parity check. These switches must be set depending on the
operation conditions.
Drive Configuration
-------------------
This magnetic disk drive consists of a disk enclosure assembly that
contains recording disks, magnetic heads, and a magnetic head drive
mechanism; one printed wiring assemblies; a frame; and a front panel.
Disk Enclosure Assembly
-----------------------
The disk enclosure assembly contains recording disks, magnetic heads,
a head carriage mechanism, a DC motor with encoder, and an air
filter. An inside-hub type DC brushless motor is used as a spindle
motor to rotate recording disks. Air can go into or come out of the
disk enclosure assembly only through the air filter provided on the
top cover off the assembly. The air in the assembly is therefore kept
highly clean.
Printed Wiring Assembly
-----------------------
The printed wiring assembly includes an SCSI interface circuit,
buffer RAM, data manager, read/write control circuit, servo control
circuit, and DC motor drive circuit to control all drive operations
and interfaces.
Dimensions
----------
Height 41.3 mm
Width 101.6 mm
Depth 157 mm
Weight 1.0 kg or less
NOTE
Front plate excluded
Interface
---------
This drive has connector J1 for connection to SCSI bus and connector
J3 for power supply. The device connected at each furthest end of the
cable must have a terminating resistor installed. If the initiator
and targets use different power supplies, power for terminating
resistor of the target should be supplied through pin 26 of the SCSI
bus.
Connetcor J1
------------
A 50-pin non-shielded connector used for interface to the SCSI bus.
Fifty-conductor flat cables and 25-signal twisted-pair cables can be
used for the SCSI bus. Cables of impedance 100 ohms 10% and
conductor diameter 28 AWG or more should be used to match the
impedance of the drive.
Example of recommended connector on the J1 cable side:
Connector J3
------------
Connector J3 for power supply is an AMP P/N 350211-1 or equivalent.
The connector housing AMP P/N 1-480424-0 of the cable suits this
connector. Select a power cable, considering the current consumption
and cable length into consideration. The connector pins must fit
here.
Features
NEC D3861 PRODUCT DESCRIPTION 806-520918-0 REV. A, 1989
Outline and Features
--------------------
The D3861 Magnetic Disk Drive has an unformatted storage capacity of
134.45 megabytes with 3.75-inch magnetic disk media and mini
Winchester magnetic heads incorporated, employing a Small Computer
System Interface (SCSI).
The magnetic head drive mechanism employs a DC motor with encoder,
achieving high-speed seek and highly reliable read/write operations.
A large capacity is also achieved with a 2-7 RLL modulation method
adopted for read/write operation.
Logical Connection to SCSI Initiator
------------------------------------
This drive operates as an SCSI target and has no initiator function.
Logical connection to the SCSI initiator is executed according to the
SCSI logical specifications.
This drive has an arbitration function for disconnection/
reconnection. It operates on the basis that the initiator has a
disconnect/reconnect function, an SCSI Message Identify signal must
be sent for a Disconnect message from the drive to indicate that the
initiator does not have that function.
In the non-arbitrating system, SCSI logical connection is executed
in the information transfer phase through the selection phase, one of
the SCSI bus phases, as a starting phase. In the arbitrating system,
SCSI logical connection is executed in the information transfer phase
through the arbitration phase and selection phase.
Detecting Drive Errors
----------------------
This drive has various self-diagnostic functions. It can read
extebded sense data with a Request Sense command of the SCSI inter-
face. You should execute a Request Sense command if an error occurs.
Diagnoses other than for errors can be executed with a Send
Diagnostic command. This drive supports the selftest specified with
a Send Diagnostic command. If an error is detected, the check
condition bit is set to '1'. The detailed diagnosis result can be
received by executing a Request Sense command.
SCSI Interface Signals
----------------------
The Unit employs a SCSI Single-Ended type interface.
The Single-Ended type interface uses a terminal resistance of 220 /
330 .
The logical specification and the electrical specification of the
signals dealt with in this section are as follows:
1. Output Characteristics