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Hard Drive: QUANTUM: Q-250 53MB 5.25"/HH SCSI1 SE

Q - 2 5 0    QUANTUM
NO MORE PRODUCED                                      Native|  Translation
Form                 5.25"/HH              Cylinders     823|     |     |
Capacity form/unform    53/      MB        Heads           4|     |     |
Seek time   / track  26.0/ 6.0 ms          Sector/track   32|     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer            14 KB FIFO BUFFER  Landing Zone
Data transfer rate    1.000 MB/S int       Bytes/Sector      512
                      1.250 MB/S ext
Recording method     RLL 1/7                        operating  | non-operating
Supply voltage     5/12 V       Temperature *C         4 50    |    -40 60
Power: sleep              W     Humidity     %         8 85    |      5 95
       standby            W     Altitude    km            3.048|        12.192
       idle          18.0 W     Shock        g         6       |     60
       seek          32.0 W     Rotation   RPM      3662
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit   96,REED SOLOMON
                                MTBF         h      25000
                                Warranty Month        12
Lift/Lock/Park     YES          Certificates     CSA,IEC380,UL478,VDE         



 +-1|                 1-----+  1-----EPROM          +1      |XX J1
 | ||                 |     |  |     |              ||      |XX
 | ||                 |     |  |     |   Terminator ||      |XX
 +-J4                 |     |  |     |              ||      |XX
    |                 |     |  |     |              ++      |XX
    |                 |     |  +-----+       Terminator+1 +1|XX
    |                 |     |                          || |||XX
    |                 |     |                 +-+A0    || |||XX
    |                 +-----MICROPROCESSOR  J6| |      || |||XX
    |                                         | |      ++ ++|XX
    |                                         | |           |1-+
    |                                         +-+P1         || |J5
    |                                                       || Factory
    |                                                       |+-+
   ++ LED                                                   |XX J2
   ++                                                       |XX Power



Jumper Setting

J5 Factory
J5 => Test connector, factory use only.

J6 Desription

            +----- WS
            | +--- A2
            | | +- A1
      | | +------- EP
      | +--------- SS
      +----------- RO

J6 A0/A1/A2 - SCSI Bus Device Identification
The SCSI bus can support up to eight devices including the host
system. Since the identity number determines the priority level of
each device, careful consideration must be taken in choosing the
correct identity number of the Q250/Q280 prior to installation.

Three shorting plugs A2, A1 and A0 are used for device identifica-
tion. These three shorting plugs comprise a 3 bit binary number in
which A2 is the most significant bit and A0 is the least significant.
Installation represents a 1, meaning that with all shorting plugs
installed the device identity is 7. With no shorting plugs installed,
the device identity would be 0.

The drive is set up as device 6 at the factory.

J6 EP - Enable Parity Option
Shorting plug option is provided so that, when installed, parity
checking of data across the SCSI bus is enabled. With EP removed,
parity is not performed.

The Q250/Q280 is shipped from the factory with parity enabled (short-
ing plug EP installed).

J6 WS - Wait Spin Option
The WS shorting plug option, when installed, will not allow the
motor to spin upon power-up until the host sends the START/STOP
command across the SCSI bus. In this way, power sequencing can be
done so that the system power supply is not overloaded by many
devices demanding peak start current at the same time. Once the
START/STOP command is received, the drive will be ready within 30

J6 SS - Self Seek Test Option
The self seek test is provided as a method to continuously exercise
the actuator of the drive. With shorting plug option SS is installed,
the drive will perform a "butterfly" seek pattern beginning with a
single track seek at the middle cylinders and extending out to a full
stroke seek. The pattern will repeat as long as power is applied to
the drive. The Q250/Q280 is shipped from the factory with the self
test disabled (shorting plug SS not installed).

J6 RO - Reset Option
The RO shorting plug when installed will allow the SCSI RST (reset)
signal to cause the drive to perform a complete reset. All drive
functions including a write to the disk will be inmediately reset.
(This may result in a partial sector to be written leading to un-
correctable read errors.) All shorting plugs, with the exception of
wait spin (WS) will be reevaluated. The drive will then perform a
complete recalibration which typically requires 200 ms to complete.

The Q250/Q280 is shipped from the factory with the complete reset
disabled (shorting plug RO not installed).

J6 P1 - Spare Shorting Plug
One spare shorting plug, labeled P1, is provided on the board. No
drive function is affected by the shorting plug. The Q250/Q280 is
shipped from the factory with the P1 shorting plug installed.

Driver Terminators
The Q200 Series disk drives contain three resistor networks, in
sockets, to terminate the collector drivers. It is important to note
that only the first device (usually the host) and the last device on
the SCSI bus should contain the terminators. When a Q250/Q280 disk
drive is used in a position of the bus other than the first or last,
all three of the terminators must be removed. The Q250/Q280 is
shipped from the factory with the terminators installed.



Notes on Installation
The Model Q250/Q280 drives may be mounted in any orientation and
have a mounting bracket with integral shock mounts for this purpose.

6-32 UNC Mounting Holes, 4 on bottom, 4 on each side (12 PL)

The base casting is very close to the drive mounting bracket. Mount-
ing screw lengths must be chosen so that no more than specified
length of screws thread protrudes through the mounting bracket holes.
This length will allow full use of the mounting hole threads and
avoid damaging or placing unwanted stress on the base casting. To
avoid stripping the mounting hole threads, the maximum torque applied
to the mounting screws must not exceed 8 inch/pounds.

Faceplate LED Operation
The LED located on the Q250/Q280 faceplate illuminates to indicate
when the drive is executing a command. It goes on at the beginning
of a command and does not go off until the command is completed or
aborted. The LED remains on even when the drive is disconnected from
the initiator during a command and also when the reset line is held
asserted (low).

The Model Q250/Q280 operates without a cooling fan provided the
ambient air temperatur does not exceed 122*F (50*C). Any user
designed cabinet should provide adequate air circulation so that this
maximum air temperature is not exceeded.

Interface Connector
One SCSI cable connector (J1) is required for the Model Q250/Q280.
Connection to J1 is through a 50-pin Universal Header connector. A
key slot is provided to prevent installing the mating connector in a
reserved direction. The recommended mating connector for J1 is AMP
receptacle P/N 1-499508-2 (w/strain relief) or P/N 1-746195-2 (w/o
strain relief), or equivalent.

 J2 DC Power and pin connector assignments
   +------------+   pin 1    +12 VDC
   | 4  3  2  1 |   pin 2    +12 Volts Return (ground)
   +------------+   pin 3    + 5 Volts Return (ground)
                    pin 4    + 5 VDC

DC power connector (J2) is a 4-pin AMP Mate-N-Lok connector P/N
350211-1 mounted on the solder side of the PCB. The recommended
mating connector (P2) is AMP P/N 1-480420-0 utilizing AMP pins P/N
350078-4 (strip) or P/N 61173-4 (loose piece). J2 pins are labeled
on the J2 connector.

 Electrical Interface
 All signals are low true and use open collector drivers terminated
 with 220 ohms to +5 volts (nominal) and 330 ohms to ground at each
 end of the cable. Resistor networks in sockets are provided on the
 Q250/Q280 to terminate the lines.

In cases where multiple devices are connected to the SCSI bus,
terminators should be removed in all but the first (host) and last
device connected to the bus.

Each signal drive by Q250/Q280 has the following output

True (Signal Assertion) = 0.0 to 0.4 Vdc as 40 mA (max),
False (Signal Non-Assertion) = 2.5 to 5.25 Vdc.

Each signal from the host to the Q250/Q280 must have the following
characteristics (measured at the drive):

True (Signal Assertion) = 0.0 to 0.4 Vdc as 40 mA (max),
False (Signal Non-Assertion) = 2.5 to 5.25 Vdc.

A receiver with hysteresis is used to meet this specification.

A 50-pin latching connector is provided at position J1 for connecting
to the standard SCSI single-ended non-shielded connection is used.
All signals are asserted at the low level. All odd pins are grounded.
(Exception is Pin 25 wich is not connected.) A maximum cable length
of 20 ft. (6 metres) is allowed.

Part Numbers
The table below provides the information necessary a unique 5-digit
part number for the two models of the Q200 Series.

 Capacity    Part Number
   53 MB     76-45000
   80 MB     76-45001

There are only two field replaceable spares for the Q250/Q280:

Description Part Number
Printd Circuit Board Assembly (PCBA) 20-22006
Shock Mount/Faceplate Assembly 75-45135



Gerneral Description
Quantum Q200 Series Disk Drives are random access storage devices
using two or three non-removable 5-1/4" rigid disk platters as
storage media.

The Model Q250/Q280 disk drives have the following key features i.e.:

 - Industry-standard (ANSI) SCSI host interface
 - Fully integrated SCSI controller
 - Half-high 5-1/4" physical size with same mounting as ST412 drives
 - Full disconnect/arbitrate/reconnect capability
 - SCSI Copy command capability
 - Transparent defect mapping
 - High-performance in-line defective sector skipping and reassignment
   of new defective sectors without need to reformat
 - Buffer memory parity
 - Patented AIRLOCK automatic shipping lock and dedicated landing zone
 - Read/Write with 1:1 interleave operation
 - Supports 512, 1024 and 2048 byte logical block sizes
 - Multiple block data transfer up to 64K blocks
 - Optional DisCache, a 60 K-byte look-ahead disk cache with programm-
   able parameters.

 Seek Time
 |                                  | Q200   |
 |Track-to-Track         msec. typ. |   6    |
 |Average                msec. typ. |  26    |
 |Full Stroke            msec. max. |  49    |
 |Latency                msec. avg. |   8.2  |

Defect Management
Q200 Series disk drives are scanned in the factory for defective
sectors on the disk. Those defective sectors are deallocated prior to
shipment. An In-Line Defect Map, duplicated on tracks on the drive
allocated for this purpose will contain the locations of all
defective sectors found in the drive.

Two sectors are allocated per cylinder as replacement sectors.
Defects found at the factory are skipped using an "In-Line" sparing
method, which replaces each sector with the next sector on the
cylinder. In the rare instance where more than two defects are found
within the same cylinder, the additional defects will be mapped into
the nearest adjacent cylinder with spare sectors available.

This approach minimizes media used for replacement and reduces access
time to the replacement sector. In addition, cylinder boundaries are
well defined, with a simple relationship between each initial
sector's physical and logical block addresses - thus providing the
host a method to ensure that file records can be stored within
cylinder boundaries for optimal accessibility.

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