
0 6 6 4 - N 1 H    IBM
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/HH               Cylinders    2857|     |     |
Capacity form/unform  2013/      MB        Heads            |     |     |
Seek time   / track  10.0/ 1.5 ms          Sector/track   94|     |     |
Controller           SCSI3 SI/WI/FA        Precompensation
Cache/Buffer           512 KB DUAL-PORTED  Landing Zone
Data transfer rate    5.220 MB/S int       Bytes/Sector      512
                     20.000 MB/S ext SYNC
Recording method     PRML 8/9                       operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C         5 55    |    -40 65
Power: sleep              W     Humidity     %         8 90    |      5 95
       standby            W     Altitude    km    -0.305  3.048| -0.305 12.192
       idle          12.7 W     Shock        g         5       |     35
       seek               W     Rotation   RPM      5400
       read/write         W     Acoustic   dBA        34
       spin-up            W     ECC        Bit   64,ON THE FLY
                                MTBF         h     750000
                                Warranty Month        60
Lift/Lock/Park     YES          Certificates     CSA,FCC,IEC380,IEC435,IEC9...

**********************************************************************
                        L   A   Y   O   U   T
**********************************************************************
IBM      0664-N1H/M1H  HARDWARE SPECIFICATION VER. 2.1, 12/21/92


  50-pin SCSI Single Ended
  ------------------------
                                                            Power
  +-SCSI-Connector-----------------------------------+-----+---------+
  | o o o o o o o o o o o o o o o o o o o o o o o o 1|     | 1 O O O |
  | o o o o o o o o o o o o o o o o o o o o o o o o o|      \-------/|
  +--------------------------------------------------+               |
  |       +---------------+Options                                   |
  |       |o o o   o o o o|Jumper                                    |
  |       |o o o o o o o o|Block                                     |
  |       +---------------+                                          |
  |                                                         +------+ |
  |                                                         |      | |
  |                                                         +------+ |
  |                                                         +------+ |
  |                                                         |      | |
  |                                                         +------+ |
  +------------------------------------------------------------------+






  68-pin SCSI Single Ended
  ------------------------
                                                            Power
  +-SCSI-Connector---------------------------1--+----------+---------+
  |  +---------------------------------------+  |          | 1 O O O |
  |  |xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|  |           \-------/|
  +---\-------------------------------------/---+                    |
  |     +-----------------+Options                                   |
  |     |o o o o o   o o o|Jumper                                    |
  |     |o o o o o o o o o|Block                                     |
  |     +-----------------+                                          |
  |                                                         +------+ |
  |                                                         |      | |
  |                                                         +------+ |
  |                                                         +------+ |
  |                                                         |      | |
  |                                                         +------+ |
  +------------------------------------------------------------------+



**********************************************************************
                      J   U   M   P   E   R   S
**********************************************************************
IBM      0664-N1H/M1H  HARDWARE SPECIFICATION VER. 2.1, 21/12/1992

 Jumper Setting
 ==============

 50-Pin SCSI
 ===========

           BLANK POLARITY -----+
         + MSB  BIT 2 ------+  |  +----------- AUTO START
 SCSI ---+      BIT 1 ---+  |  |  |  +-------- -MASTER SYNC
 Address + LSB  BIT 0 +  |  |  |  |  |  +----- +TERM POWER
                      |  |  |  |  |  |  |  +-- LED ANODE
                    +--+--+--+--+--+--+--+--+
                    |B1|B2|B3|  |B5|B7|B8|B9|
                    +--+--+--+--+--+--+--+--+
                    |A1|A2|A3|A6|A5|A7|A8|A9|
                    +--+--+--+--+--+--+--+--+
         Ground Pins -+--+--+  |  |  |  |  +-- LED CATHODE
        Option Pin * ----------+  |  |  +----- -TERM POWER
                                  |  +-------- -SLAVE SYNC
                                  +----------- Ground
 NOTE
 If the Auto Start Shunt is not on, the disk starts by SCSI command
 only.

 * Option Pin
   The 0664 Option pin (A6) is a TTL input to the 0664 Controller.


 68-Pin SCSI
 ===========

         + MSB  BIT 3 ---------+  +-------------- AUTO START
         +      BIT 2 ------+  |  |  +----------- BLANK POLARITY
 SCSI ---+      BIT 1 ---+  |  |  |  |  +-------- -MASTER SYNC
 Address + LSB  BIT 0 +  |  |  |  |  |  |  +----- +TERM POWER
                      |  |  |  |  |  |  |  |  +-- LED ANODE
                    +--+--+--+--+--+--+--+--+--+
                    |B1|B2|B3|B4|B5|  |B7|B8|B9|
                    +--+--+--+--+--+--+--+--+--+
                    |A1|A2|A3|A4|A5|A6|A7|A8|A9|
                    +--+--+--+--+--+--+--+--+--+
         Ground Pins -+--+--+--+--+ |  |  |  +-- LED CATHODE
                                    |  |  +----- -TERM POWER
                                    |  +-------- -SLAVE SYNC
                                    +----------- * OPTION PIN

 NOTE
 If the Auto Start Shunt is not on, the disk starts by SCSI command
 only.

 * Option Pin
   The 0664 Option pin (A6) is a TTL input to the 0664 Controller.


 50-Pin SCSI ID
 --------------
   +----------+-----------------------+
   | SCSI ID  | MSB             LSB   |
   |          | B3    | B2    | B1    |
   +----------+-------+-------+-------+
   |    0     | OPEN  | OPEN  | OPEN  |
   |    1     | OPEN  | OPEN  | CLOSED|
   |    2     | OPEN  | CLOSED| OPEN  |
   |    3     | OPEN  | CLOSED| CLOSED|
   |    4     | CLOSED| OPEN  | OPEN  |
   |    5     | CLOSED| OPEN  | CLOSED|
   |    6     | CLOSED| CLOSED| OPEN  |
   |    7     | CLOSED| CLOSED| CLOSED|
   +----------+-------+-------+-------+


 68-Pin SCSI ID
 --------------
   +----------+-------------------------------+
   | SCSI ID  |       Jumper Location         |
   |          |             PINS              |
   |          |  B4   |  B3   |  B2   |  B1   |
   +----------+-------+-------+-------+-------+
   |    0     | OPEN  | OPEN  | OPEN  | OPEN  |
   |    1     | OPEN  | OPEN  | OPEN  | CLOSED|
   |    2     | OPEN  | OPEN  | CLOSED| OPEN  |
   |    3     | OPEN  | OPEN  | CLOSED| CLOSED|
   |    4     | OPEN  | CLOSED| OPEN  | OPEN  |
   |    5     | OPEN  | CLOSED| OPEN  | CLOSED|
   |    6     | OPEN  | CLOSED| CLOSED| OPEN  |
   |    7     | OPEN  | CLOSED| CLOSED| CLOSED|
   |    8     | CLOSED| OPEN  | OPEN  | OPEN  |
   |    9     | CLOSED| OPEN  | OPEN  | CLOSED|
   |   10     | CLOSED| OPEN  | CLOSED| OPEN  |
   |   11     | CLOSED| OPEN  | CLOSED| CLOSED|
   |   12     | CLOSED| CLOSED| OPEN  | OPEN  |
   |   13     | CLOSED| CLOSED| OPEN  | CLOSED|
   |   14     | CLOSED| CLOSED| CLOSED| OPEN  |
   |   15     | CLOSED| CLOSED| CLOSED| CLOSED|
   +----------+-------+-------+-------+-------+


 LED Pins
 --------
 The LED pins (A9/B9 on the Option block) can be used to drive an
 external LED. The LED cathode should be connected to pin A9 of the
 option block, and the LED anode should be connected to pin B9 of the
 option Block.

 The 0664 products provides up to 20mA of TTL level drive capability.


 SCSI Bus Termination Power
 --------------------------
 Termination Power is optionally provided for systems that desire to
 use it. In order to use the 0664 termination power, the user needs to
 install a jumper between pins B8 and A8 of the Options block. The
 jumper should only be installed on device, which should be the last
 device on the SCSI bus (i.e. The HD that is physically closest to the
 terminator). 0664 68-pin models can source up to 2.0 Amps of current
 at 5.0 volts ( 5%) for termination power. 0664 50-pin models can
 source up to 1.5 Amps of current at 5.0 volts ( 5%) for termination
 power.



**********************************************************************
                      I   N   S   T   A   L   L
**********************************************************************
IBM      0664-N1H/M1H  HARDWARE SPECIFICATION VER. 2.1, 12/21/92

 Notes On Installation
 =====================

 Installation direction
 ----------------------

     horizontally                           vertically
   +-----------------+             +--+                       +--+
   |                 |             |  +-----+           +-----+  |
   |                 |             |  |     |           |     |  |
 +-+-----------------+-+           |  |     |           |     |  |
 +---------------------+           |  |     |           |     |  |
                                   |  |     |           |     |  |
                                   |  |     |           |     |  |
 +---------------------+           |  +-----+           +-----+  |
 +-+-----------------+-+           +--+                       +--+
   |                 |
   |                 |
   +-----------------+


 Mounting
 --------
 The drive can be mounted with any surface facing down.

 The drive is available with both side and bottom mounting holes.

 The maximum allowable penetration of the mounting screws is 3.8 mm.

 The torque applied to the mounting screws must be 1.0 Newton-meters
   0.1 Newton-meters.

 WARNING
 The file's mounting frame is electrically isolated from the file's
 disk enclosure. The disk enclosure is not at ground potential. There-
 fore any user mounting scheme must not result in the disk enclosure
 being shorted to ground. Screws 6-32.


 Clearances
 ----------
 A minimum of 2 mm clearance should be given to the bottom surface
 except for a 10mm diameter area around the bottom mounting holes. For
 proper cooling it is suggested that a clearance of 6 mm be provided
 under the file and on top of the file.

 Precaution must be taken so as not to block any of the vent holes on
 the side file.

 NOTE
 The top of the drive will not exceed the height dimension by more
 than 2 millimeters during a non-operating shock.


 Power Connector
 ---------------
 The DC power connector used in 0664 is a Molex 8981-4V6. It is
 designed to mate with a Molex 8981-4P4 crimp connector, or a Molex
 A-70156-2000 insulator displacement connector, or their equivalent.

   +------------+   pin 1    +12 VDC
   | 1  2  3  4 |   pin 2    +12 Volts Return
   +------------+   pin 3    + 5 Volts Return
                    pin 4    + 5 VDC


 50-Pin SCSI Bus Connector
 -------------------------
 0664 50-pin models use a Molex 50-pin connector p/n 70247. This
 connector is compatible with the ANSI SCSI-2 "A" connector specifica-
 tions. It is limited to 8 bit data transfers only.


 68-Pin SCSI Bus Connector
 -------------------------
 0664 68-pin models use a Molex 68-pin connector p/n 15-87-0311. This
 connector is compatible with the ANSI SCSI-3 "P" connector specifica-
 tions. It can transfer data in both 8 bit (narrow) and 16 bit (wide)
 modes.

 NOTE
 Note that the "P" connector is not compatible with the 50-pin "A"
 connector as defined in the ANSI SCSI-2 standard. Therefore system
 cables used with 50 pin products cannot be plugged directly into the
 68 pin models.

 Despite the difference in connector, the 0664 68-pin models are
 electrically compatible with 0664 50-pin models and other 50-pin
 single ended SCSI products and therefore can coexist on the same bus.
 In order to do so, the differences in connector types would need to
 be accounted for in the cable.


 Single Ended SCSI Cable
 -----------------------
 The 0664 disk drive uses single ended drivers and receivers which
 will permit cable lengths of up to 6 meters (19.68 feet). It should
 be noted however that users who plan to use 0664 in fast mode should
 follow all of the SCSI-3 guidelines for single ended fast operations.
 This may include a cable length of less than 6 meters.

 The SCSI-2 standard states that the total stub of the cable must not
 exceed 0.1 meters. This file has a maximum internal stub length of
 0.077 meters on all SCSI signals. To remain compliant with the
 standard, the SCSI bus cable must not add more than 0.023 meters
 addtional stub length to any of the SCSI signals.


 SCSI Bus Terminators
 --------------------
 0664 has no internal SCSI bus terminators. The system is responsible
 for properly terminating the SCSI bus. A regulated 110 Ohm terminator
 is recommended for reliable fast operations (i.e. transfer speeds
 greater than 5MB transfer/sec.). Split resistor or regulated
 terminations may be used for systems that do not plan fast data
 transfers. Some of the terminator possibilities for 0664 are listed
 in the following table.
 +---------------+--------------------------+------------------------+
 |Data Transfer  | 50 Pin Model Terminators |68 Pin Model Terminators|
 |Rates          |                          |                        |
 +---------------+--------------------------+------------------------+
 |less than 5M   | Data Mate DM500-06-0     |Data Mate DM2050-02-68S |
 |transfers/sec  | Data Mate DM500-06-R     |Data Mate DM2050-02-68R |
 |               | Data Mate DM2000-02-R    |                        |
 +---------------+--------------------------+------------------------+
 |more than 5M   | Data Mate DM500-06-R     |Data Mate DM2050-02-68R |
 |transfers/sec  | Data Mate DM2000-02-R    |                        |
 +---------------+--------------------------+------------------------+


 SCSI Bus Termination Power
 --------------------------
 Termination power is optionally provided for systems that desire to
 use it. In order to use the 0664 termination power, the user needs to
 install a jumper between pins B8 and A8 of the Option block. The
 jumper should only be installed on one device, which should be the
 last device on the SCSI bus (i.e. the file that is physically closest
 to the terminator). 0664 68 pin models can source up to 2.0 Amps of
 current at 5.0 Volts ( 5%) for termination power. 0664 50 pin models
 can source up to 1.5 Amps of current at 5.0 Volts ( 5%) for
 termination power.


 Recommendations For SCSI Bus Noise Reduction
 --------------------------------------------
 The SCSI commitee has spent a large amount of resource looking into
 what needs to be done to assure SCSI devices will work as specified
 in the SCSI-2 standard. As a result of this, the committee is
 recommending the following approach:

 1. Use the regulated 110 ohm terminator
 2. Use AWG 28 polyolefin shielded cables
 3. Make sure data and parity are on the outer ring of the cable and
    that REQ and ACK are in the core of the cable.


 SCSI Bus Electrical Characteristics
 -----------------------------------
 0664 products use single ended transeivers. The following DC operat-
 ing characteristics pertain to the 0664 SCSI bus transceivers. All of
 these parameters meet the ANSI SCSI-2 requirements.

 Ta = 0 to 70 deg. C
  +------+--------------------------+---+---+-----+---------------+
  |Symbol|Input Characteristics     |Min|Max|Units|Conditions     |
  +------+--------------------------+---+---+-----+---------------+
  |Vol   |Low level output voltage  |   |0.4| V   |lout = 48.0 mA |
  +------+--------------------------+---+---+-----+---------------+
  |Voh   |High level output voltage |2.5|   | V   |lout = -400  A |
  +------+--------------------------+---+---+-----+---------------+
  |Vil   |Low level input voltage   |0.0|0.8| V   |               |
  +------+--------------------------+---+---+-----+---------------+
  |Vih   |High level input voltage  |2.0|5.5| V   |               |
  +------+--------------------------+---+---+-----+---------------+
  |Iil   |Low level input current   |   |10 |  A  |               |
  +------+--------------------------+---+---+-----+---------------+
  |Iih   |High level input current  |   |50 |  A  |               |
  +------+--------------------------+---+---+-----+---------------+
  |Vihys |Input hysterisis          |0.4|   | V   |               |
  +------+--------------------------+---+---+-----+---------------+
  |Ci    |Input capacitance         |   |25 | pF  |               |
  +------+--------------------------+---+---+-----+---------------+


 Spindle Synchronization
 -----------------------
 Spindle Synchronization Overview: There are four modes of spindle
 synchronization. The following paragraphs give a short description of
 each spindle synchonization mode:

 - The Slave drive, (Slave Sync mode) receives the index from the
   Master on the -SLAVE SYNC line and synchronizes its index (Slave
   index) to it.
 - Should the drive be the Master, (Master Sync mode), it outputs its
   index on the -MASTER SYNC a -SLAVE SYNC lines. The Master drive
   does not synchronize its index to any other device. It simply
   outputs its index.
 - In the Master Sync Control mode, a drive will synchronize its
   spindle to the signal it receives on the -SLAVE SYNC input. It
   outputs to -MASTER SYNC a pulse that has the same period as the
   file INDEX, but is not synchronized to the file INDEX generated
   from the disk.
 - In the non-sync mode, the file will receive the -SLAVE SYNC signal,
   but it is not used by the file.
    +--------------------------------------------------+
    |     Spindle Synchronization Control Lines        |
    +--------------+--------------+--------------------+
    |-MASTER SYNC  | -SLAVE SYNC  | function mode      |
    +--------------+--------------+--------------------+
    | released     |  receive     | Slave sync         |
    +--------------+--------------+--------------------+
    | drive        |  drive       | Master Sync        |
    +--------------+--------------+--------------------+
    | drive        |  drive       | Master Sync Control|
    +--------------+--------------+--------------------+
    | released     |  receive     | non sync.          |
    +--------------+--------------+--------------------+

 - Drive Synchronization with Offset
   The drive electronics receives the Master Index and creates the
   delayed Slave Index, which has the same nominal period as the file
   INDEX, but is not synchronized to the file INDEX generated from the
   drive. The delay is determined by using the SCSI Mode Select
   command, Rigid Disk Drive Geometry Parameters. A rotational offset
   of 0/256 of a revolution up to 255/256 of a revolution may
   selected in increments of 1/256 of a revolution.

 - Synchronization Time
   It could take up to 1.5 seconds (1 second nominally) to synchronize
   the Slave drive to the Master. If the Slave drive is synchronizing
   to the Master, it will not be able to read or write data. Once
   synchronized, the file will maintain   20 usec synchronization
   tolerance.

 - Spindle Synchronization Bus
   The spindle synchronization Bus consists of the two signal lines,
   -MASTER SYNC and -SLAVE SYNC.

 - Termination
   Bus termination of the -MASTER SYNC and -SLAVE SYNC signals is
   internal to the drive. These two signals each have a 2000 ohm
   pullup to the drives +5V supply. A maximum of 16 drives can have
   their -MASTER SYNC or -SLAVE SYNC lines daisy chained together.
   Violating this could damage the Master drivers on the -MASTER SYNC
   and/or -SLAVE SYNC lines.

   It is the using systems responsibility to provide the cable to
   connect to the -SLAVE SYNC and -MASTER SYNC pins.

 - Bus Characteristics
   - maximum Bus length = 6 meters

   - 4 micro-second minimum negative active pulse

   - 0.8 volts = valid low input

   - 2.0 volts = valid high input

   - 0.4 volts = low output

   - 64 milli-amps = maximum output low level sink current

   - high level output set by termination resistors

   The drivers used for these two signals are open collector buffers.



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
IBM      0664-N1H/M1H  HARDWARE SPECIFICATION VER. 2.1, 12/21/1992


 Features
 --------
 - Industry-standard interface: ANSI/SCSI-2 (optional 68 pin from
   SCSI-3)
 - Fast SCSI supported
 - Wide SCSI mode
 - Thermal compensation on each data surface for improving on-track
   positioning capability
 - SCSI disconnect and reconnect capability
 - SCSI bus parity
 - Multiple initiator support
 - Closed-loop actuator servo (dedicated disk servo surface plus data
   reference)
 - Rotary voice coil motor actuator
 - Automatic actuator lock
 - Dedicated head landing zone
 - (0.4/4) 8/9 rate encoding
 - read-ahead caching
 - 512K byte, multi-segmented, dual port data buffer
 - Write-Back caching supported (delayed write)
 - command recordering
 - Back-to-back writes
 - Automatic power management
 - Scatter/Gather read and write commands
 - Tagged and Untagged command queuing
 - Automatic sector reallocation
 - Variable logical block length (256-744 supported)
 - Down-loadable SCSI firmware
 - Buffer memory parity
 - Self-diagnostics on power up
 - Automatic retry and data correction on read errors
 - In-line alternate sector assignment for high performance
 - Probability of not recovering data: 1 in 10(15) bits read
 - All mounting orientations supported
 - No preventative maintenance required
 - Two field Replaceable Units (FRU's:): Electronics or File
 - Predictive Failure Analysis (PFA)
 - Longitudinal Redundancy Code (LRC)
 - ECC on the fly
 - Error logging and analysis
 - Deep Data Recovery Procedures (DRP)
 - Magnetoresistive (MR) heads
 - Partial Response Maximum Likelihood (PRML) data channel with
   digital filter
 - Spindle synchronization supported
 - LED Driver supported

 Please Note: The 0664 frame supports Industry Standard mounting holes
 on the sides and bottom, as well as IBM's bottom mounting holes
 which are common with the old IBM frame.

 User Awareness: The 0664 drive has a new look as compared to previous
 3  family members from IBM. A piece of Kapton tape is wrapped around
 the entire drive, both the frame and DE. This tape is used as a
 stiffener to improve the vibration tolerance of the file.


 Hot plug/unplug support
 -----------------------
 Power supply and SCSI bus hot plug and un-plug is allowed. There is
 no special sequence required for connecting 5 volts, 12 volts, or
 ground. During a hot plug-in event the file being plugged will draw a
 large amount of current at the instant of plug-in. This current spike
 is due to charging the bypass capacitors on the file. This current
 pulse may cause the power supply to go out of regulation. If this
 supply is shared by other files then a low voltage power on reset may
 be initiated on those files. Therefore the recommendation for hot
 plugging is to have one supply for each file. Never daisy chain the
 power leads if hot plugging is planned. Hot plugging should be
 minimized to prevent wear on the power connector.

 Hot plugging the SCSI bus may cause glitches on the bus. To minimize
 the chance of glitching, it is recommended to plug in the SCSI bus
 before the power is applied.

 During hot plugging, the supplies must not go over the upper voltage
 limit. This means that proper ESD protection must be used during the
 plugging event.


 Microcode Defect Rate
 ---------------------
 The interface microprocessor code target defect rate will be less
 than or equal to 0.150 total valid unique APARS per thousand lines
 of new/changed source instructions (TVUA/KCSI) for the 60 month
 product life APAR (Authorized Program Analysis Report) as defined
 here, is a report of a problem caused by a suspected defect in the
 current unaltered release of 0664 microcode.


 Acoustics Levels
 ----------------
 Upper Limit Sound Power Requirements (Bels)
 +---------+----------------------------------+-------------+
 |         |Octave Band Center Frequency (Hz) | A-weighted  |
 +---------+----+----+----+----+----+----+----+-------------+
 |Mode     | 125| 250| 500| 1 k| 2 k| 4 k| 8 k|Max. Sum     |
 +---------+----+----+----+----+----+----+----+-------------+
 |Idling   | 4.5| 3.5| 3.3| 3.5| 4.3| 4.3| 4.0|   4.75      |
 +---------+----+----+----+----+----+----+----+-------------+
 |Operating| 4.5| 4.0| 3.6| 3.8| 4.6| 4.6| 4.3|   5.00      |
 +---------+----+----+----+----+----+----+----+-------------+
 The above sound power levels are statistical upper limits of the
 sound power levels.

 Additionally, the population average of the sound pressure measured
 one meter above the center of the drive will not exceed 34 dB.

 NOTE
 The operating mode is simulated by seeking at a rate between 12 and
 15 seeks per second.


 Description of the Differential Models
 ======================================
 This section details all the differences of the Differential 0664
 models, as compared to the single-ended models which are referenced
 throughout the other sections of this document. The differential
 interface is provided to the customer by plugging a differential
 conversion card onto either of our single-ended models.

 Different E/C part numbers exist for the Differential models, please
 see your IBM Customer Representative to obtain these numbers.


 Power Differences for Differential SCSI
 ---------------------------------------
 In addition to the current required by the 0664 file, the 50 Pin
 SCSI Differential Adapter Card requires an additional 0.240A to
 0.260A while idle. While reading or writing, the average additional
 current is 0.5A with peaks of 1.1A.

 At present, the 68 Pin SCSI Differential Adapter Cards current are
 estimated to use an additional 0.336A to 0.364A while idle and an
 average of 0.7A with 1.54A peaks when reading or writing.


 Differential 50 Pin Signal Connector
 ------------------------------------
 Differential 0664 50 pin models use a Molex 50 pin connector p/n
 70246. This connector is compatible with the ANSI SCSI-2 "A"
 connector specifications. It is limited to 8 bit data transfers only.


 Differential 68 Pin Signal Connector
 ------------------------------------
 Differential 0664 68 pin models use a Molex 68 pin connector p/n
 15-87-0311. This connector is compatible with the ANSI SCSI-3 "P"
 connector specifications. It can transfer data in both 8 bit (narrow)
 and 16 bit (wide) modes.

 Note that the "P" connector is not compatible with the 50-pin "A"
 connector as defined in the ANSI SCSI-2 standard. Therefore system
 cables used with 50-pin product cannot be plugged directly into the
 Differential 0664 68 pin models.

 Despite the difference in connector, the Differential 0664 68-pin
 models are electrically compatible with Differential 0664 50-pin
 models an dother 50 pin differential SCSI products and therefore can
 coexist on the same bus. In order to do so, the differences in
 connector types would need to be accounted for in the cable.


 Differential SCSI Bus Cable
 ---------------------------
 Cables must meet the requirements for differential cables as set
 forth in the ANSI SCSI-2 standard under "Cable Requirements -
 Differential Cable". Cable length of up to 25 meters are supported.


 Differential SCSI Bus Terminators
 ---------------------------------
 Differential 0664 has no internal SCSI bus terminator. The system is
 responsible for properly terminating the SCSI bus. Any terminator
 thats meets the SCSI standard for differential terminator should be
 acceptable.
  +------------------+----------------------+------------------------+
  |Data Transfer     | 50 Pin Model         | 68 Pin Model           |
  |Rates             | Terminators          | Terminators            |
  +------------------+----------------------+------------------------+
  |10M transfers/sec | Data Mate DM550-05-0 | Data Mate DM2050-01-68D|
  |or less           | Data Mate DM1050-02-0|                        |
  +------------------+----------------------+------------------------+



**********************************************************************
                      G   E   N   E   R   A   L
**********************************************************************
IBM       0664-N1H/M1H

 Differential Models
 -------------------
 For each model of the 0664 the option of a differential interface is
 provided. The differential interface is provided to the customer by
 plugging a differential conversion card onto either of single-ended
 models.


