
A - 5 2 0 A T    AREAL
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 2.5"/SUPERSLIMLINE    Cylinders        | 1020|     |
Capacity form/unform   526/      MB        Heads           6|   16|     |
Seek time   / track  13.0/ 3.0 ms          Sector/track     |   63|     |
Controller           IDE / AT              Precompensation
Cache/Buffer            32 KB READ-AHEAD   Landing Zone
Data transfer rate    2.500 MB/S int       Bytes/Sector      512
                      4.000 MB/S ext
Recording method     RLL 1/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5 V          Temperature *C         5 55    |    -40 60
Power: sleep              W     Humidity     %         8 80    |      8 80
       standby        0.1 W     Altitude    km    -0.061  3.048| -0.061 12.192
       idle           1.5 W     Shock        g        50       |    100
       seek           2.5 W     Rotation   RPM      3600
       read/write     2.3 W     Acoustic   dBA        35
       spin-up        6.0 W     ECC        Bit   88,REED SOLOMON
                                MTBF         h     150000
                                Warranty Month        24
Lift/Lock/Park     YES          Certificates     CSA,TUV,UL1950,VDE           

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                        L   A   Y   O   U   T
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AREAL    A520 TECHNICAL MANUAL P/N 12986 REV. 1.0, JUNE 15, 1994

  +---------------------------------------------------------+
  |                                                         |
  |                                                         |XX44
  |                                                         |XX
  |         PCBA SIDE                                       |XX I
  |                                                         |XX N
  |                                                         |XX T
  |                                                         |XX E
  |                                                         |X* R
  |                                                         |XX F
  |                                                         |XX A
  |                                                         |XX C
  |                                                         |XX E
  |                                                         |XX
  |                                                         |XX
  |                                                         |  2
  |                                                         |XXJP1
  |                                                         |XXB
  +---------------------------------------------------------+



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                      J   U   M   P   E   R   S
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AREAL    A520  TECHNICAL MANUAL P/N 12986 REV. 1.0, JUNE 15, 1994

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

 x = Factory default configuration


 JP1  Master/Slave Configuration
 -------------------------------
 43-------------------------------------------------+
 |o o o o o o o o o o o o o o o o o o o o o 1 k C A |
 |o o o o o o o o o o o o k o o o o o o o o 2 k D B |
 +--------------------------------------------------+

 Interface Pins C and D

   OPEN    Master x
   CLOSED  Slave

 k = removed pins



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                      I   N   S   T   A   L   L
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AREAL    A520  TECHNICAL MANUAL P/N 12986 REV. 1.0, JUNE 15, 1994

 Notes on Installation
 =====================

 Recommended Mounting Configuration
 ----------------------------------

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

 This drive is designed to be used in applications where the unit may
 experience extreme levels of both shock and vibration. There are no
 limits on mounting orientation and mounting clearance is not
 required. Maximum insertion length of the 3 mm x .5 screws is 0.118"
 (3.00 mm).


 Cabling
 -------
 All 2.5 inch AT/IDE interface drives use a 44 pin male connector that
 incorporates power, control, and data signals. This configuration
 differs from the 3.5 inch IDE drives which employ a 40 pin signal
 connector and separate 4 pin power connector. Therefore, if you are
 replacing an existing 3.5 inch disk drive and are faced with a 40 pin
 connector, you will need an adapter card (part #10421). If your
 computer was designed for 2.5" hard drives, there will be a 44 pin
 connection on the motherboard.

 Since power and ground are present at the interface connector, damage
 could be induced by offset or upside down connection. Please ensure
 that pin 20 of your system's female connector is properly keyed.


    Adapter Board
    -------------

                    GND +5VDC
                 +----+-++
                 |O O O O|
     ++          +-----+-+
     |+- Pin 44        |         ++
     |+----------------+  +------++ Pin 40
     |+-------------------++-----++
     |+--------------------++----++
     |+---------------------++---++
     |+----------------------+
                                 ||
     ||                          ||
     ||                          ||
     |+-----------------------+
     ++Pin 1                  +--++ Pin 1
                                 ++


 Physical Connection - AT Interface
 ----------------------------------
 Both power and control signals are supplied to the drive through a
 single 44 pin cable. Please note that separate power is supplied to
 the logic and motor circuits to minimize noise coupling.

 Maximum length of this 44 pin cable is 18 inches (457 mm) since it is
 TTL driven. Two drives may be daisy chained on this cable, however,
 the cable remains restricted to 18 inches.

 Recommended mating connectors are as follows:

 +-------------------+-------------+---------+-------------------+
 |Connector Style    |    3M       |Dupont   | Elco              |
 +-------------------+-------------+---------+-------------------+
 |Flex Cable         |N/A          |86456-044|N/A                |
 +-------------------+-------------+---------+-------------------+
 |Ribbon Cable       |N/A          |N/A      |20-8394-2044-04-101|
 +-------------------+-------------+---------+-------------------+
 |PCBA Straight      |N/A          |86455-044|20-8390-2044-00-101|
 +-------------------+-------------+---------+-------------------+
 |PCBA Rigth Angle   |             |         |                   |
 |Areal Org. Height  |150250-5122TH|N/A      |N/A                |
 |MCC Spec Height    |150250-5222TH|88333-044|20-8390-2044-04-101|
 +-------------------+-------------+---------+-------------------+


 Electrical Description - AT Interface
 -------------------------------------
 All signal levels are TTL compatible. A logic "1" is from 2.0 volts
 to 5.0 volts. A logic "0" is from 0.0 volts to 0.7 volts.

 The interface between the drive adapter and the drive is termed the
 "Host Interface". The set of registers in the I/O space of the Host
 is known as the "Task File".

 All signals on the Host Interface have the prefix Host. All negativ-
 ely active signals are prefixed with a "-" designation. All positiv-
 ely signals are prefixed with a "+" designation. Signals whose source
 is the Host are "outbound" and those whose source is the drive are
 "inbound".

      +------+-------------------+------+----------------+
      | Pin  | Signal            | Pin  | Signal         |
      +------+-------------------+------+----------------+
      | 01   | -Host Reset       | 02   |  Gnd           |
      +------+-------------------+------+----------------+
      | 03   | +Host Data 7      | 04   | +Host Data  8  |
      +------+-------------------+------+----------------+
      | 05   | +Host Data 6      | 06   | +Host Data  9  |
      +------+-------------------+------+----------------+
      | 07   | +Host Data 5      | 08   | +Host Data 10  |
      +------+-------------------+------+----------------+
      | 09   | +Host Data 4      | 10   | +Host Data 11  |
      +------+-------------------+------+----------------+
      | 11   | +Host Data 3      | 12   | +Host Data 12  |
      +------+-------------------+------+----------------+
      | 13   | +Host Data 2      | 14   | +Host Data 13  |
      +------+-------------------+------+----------------+
      | 15   | +Host Data 1      | 16   | +Host Data 14  |
      +------+-------------------+------+----------------+
      | 17   | +Host Data 0      | 18   | +Host Data 15  |
      +------+-------------------+------+----------------+
      | 19   |  Gnd              | 20   |  Key           |
      +------+-------------------+------+----------------+
      | 21   | Not Connected     | 22   |  Gnd           |
      +------+-------------------+------+----------------+
      | 23   | -Host IOW         | 24   |  Gnd           |
      +------+-------------------+------+----------------+
      | 25   | -Host IOR         | 26   |  Gnd           |
      +------+-------------------+------+----------------+
      | 27   | -IOCHRDY          | 28   |  Not Connected |
      +------+-------------------+------+----------------+
      | 29   | Not Used          | 30   |  Gnd           |
      +------+-------------------+------+----------------+
      | 31   | +Host IRQ         | 32   | -Host IO16     |
      +------+-------------------+------+----------------+
      | 33   | +Host Address 1   | 34   | -Host PDIAG    |
      +------+-------------------+------+----------------+
      | 35   | +Host Address 0   | 36   | +Host Address 2|
      +------+-------------------+------+----------------+
      | 37   | -Host CS0         | 38   | -Host CS1      |
      +------+-------------------+------+----------------+
      | 39   | -Host Active/Slave| 40   |  Gnd           |
      +------+-------------------+------+----------------+
      | 41   | +5 Volt Logic     | 42   | +5 Volt Motor  |
      +------+-------------------+------+----------------+
      | 43   |  Gnd              | 44   | +AT Interface  |
      +------+-------------------+------+----------------+
      +------+-------------------+------+----------------+
      | E    |  NO PIN           |  F   | NO PIN         |
      +------+-------------------+------+----------------+
      | C    |  Master/Slave     |  D   | Master/Slave   |
      +------+-------------------+------+----------------+
      | A    |  Test Only        |  B   | Test Only      |
      +------+-------------------+------+----------------+


 Air Filtration System
 ---------------------
 Recirculated air is forced through an electrostatic filter, providing
 a clean environment for the recording heads and disks.



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                      F   E   A   T   U   R   E  S
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AREAL    A520  TECHNICAL MANUAL P/N 12986 REV. 1.0, JUNE 15, 1994

 Introduction
 ------------
 Areal Model A520 is a 2.5 inch, high capacity, rugged, high
 performance, low power, low profile disk drive. By design, it is
 ideal for notebook, laptop, or portable applications.

 The A520 incorporate the IBM PC-AT Task File control logic and
 requires only chip select decode logic to allow bus connection. This
 logic is typically embedded in your computer motherboard.


 Overview
 --------
 This Technical Manual describes all physical and electrical
 characteristics necessary to utilize the A520 in AT mode.

 Key Features:

 - Automatic Microprocessor Controlled Diagnostics

 - Automatic Read Look Ahead

 - Buffer Size of 32 KB, 64 KB or 128 KB

 - Embedded Servo System with DSP Control

 - Extremely Low Power Requirement

 - Internal Air Filtration System

 - Lightweight at Less than 5 Ounces

 - Programmable Low Power Modes

 - Reed Solomon Error Correction on the Fly

 - Constant Density Recording Method

 - 100 G Non-Operating Shock Tolerance



 Functional Description
 ----------------------
 The A520 contains all necessary mechanical and electronic parts
 to interpret control signals, position the heads, read and write
 data, and provide a contaminant free environment for the heads and
 disks.


 Drive Mechanism
 ---------------
 A brushless DC motor rotates the spindle at 3600 RPM. Back EMF of the
 motor is used to quickly stop the spindle when power is removed.


 Head Positioner Mechanism
 -------------------------
 The read/write heads are positioned by a rotary voice coil actuator
 which employs DSP control to ensure seek accuracy.


 Setup Table Alteration
 ----------------------
 Whenever a peripheral device is changed or added, your computer's
 CMOS table may require modification. This table is typically
 accessed at power on by pressing the "Del" key, or by running the
 "Setup" program.

 Once inside this setup program, you will be prompted for various
 parameters, but only need to specify the number of heads, sectors,
 and cylinders. Other variables such as write current, landing zone,
 etc., are determined by Areal engineering during the design phase
 and are hard coded into the drive. The A520 is most efficient when
 specified as a 16 head, 63 sector, 1020 cylinder device. These exact
 parameters may not be available as an existing drive type. If this is
 the case, please locate the user definable BIOS entry (typically
 47,48 or 49) and enter the parameter listed above. From these
 parameters, you can calculate total capacity of the A520 for example
 as 1020 x 16 x 63 x 512 = 526,417,920 bytes, however, even on a
 freshly formatted disk this total capacity cannot be used by the
 user, since some data space is used by the operating system for
 directory space, etc.

 Most programs report capacity in this '526 million byte' format,
 however, some programs such as FDISK still use the old standard of
 'megabytes'. In the megabyte measurement, total byte capacity is
 devided by 1.024 x 1.024, reducing the reported capacity to 502
 megabytes.


 Formatting
 ----------
 Once the drive has been partitioned, DOS requires that it be format-
 ted. Formatting checks for defective sectors (and deallocates them if
 necessary) and builds the FAT (file allocation table). Make sure to
 use the "/s" option so that your hard drive will be bootable.

 Example: type "FORMAT C:/S". Format will only recognize hard drives
 that have valid DOS partitions, therefore FDISK must precede
 formatting.

 If an "Invalid Drive Specification" error is reported, the drive has
 not successfully been partitioned. Please run FDISK once more.

 To format the drive with other operating systems, see the manuals
 that came with the system.


 Seek Time
 ---------
       +----------------------------------+--------+
       |                                  |  A520  |
       +----------------------------------+--------+
       |Track-to-Track         msec. typ. |   3    |
       +----------------------------------+--------+
       |Average                msec. typ. |  13.0  |
       |                       msec. max. |  25    |
       +----------------------------------+--------+
       |Latency                msec. avg. |   8.33 |
       +----------------------------------+--------+


 Read Look Ahead
 ---------------
 Read look ahead will improve the read performance of the drive when
 sequential data is requested. When a Read command is issued to the
 drive the requested data is put into the read look ahead buffer. The
 drive will then continue to look ahead and read the remaining sectors
 until the buffer is full. This process will be interrupted if the
 drive receives another command.


 Write Cache
 -----------
 Write cache will improve system performance under normal operations
 involving writes to the drive. The write data is put into the high
 speed memory buffer before being written to the actual disk, thus
 freeing the host system to perform other tasks.


 Read/Write and Control Electronics
 ----------------------------------
 Internally, a single preamp IC is mounted in close proximity to the
 heads to control head selection, read preamplification, and the write
 data circuitry.

 The microprocessor controlled circuit board provides the remaining
 electronic functions which include:

 - Spindle Motor Control
 - Power Management
 - Rotary Actuator Control
 - Interface Control
 - Read/Write Circuitry
 - Spin Speed Control

 The microprocessor performs an extensive battery of tests when power
 is applied and will not come READY is an error is detected.


 Read/Write Heads and Disks
 --------------------------
 Data is recorded on 65 mm diameter glass disk(s) using thin film
 heads.


 Error Correction
 ----------------
 The A520 employs an 88 bit Reed Solomon polynominal for Data
 Field error detection and correction, plus a 16 bit CRC code for ID
 Field error detection. Single 11 bit burst can be corrected on the
 fly.


 Execute Drive Diagnostic Command -90
 ------------------------------------
 This command directs the drive(s) to perform internal diagnostic
 tests. The DRV bit is ignored.

 In a single drive system, drive 0 performs the following sequence:

 1. complete its diagnostics and post the results

 2. clear BSY and generate an interrupt


 In a dual drive system, drive 0 performs the following sequence:

 1. complete its diagnostics

 2. wait for the slave to report its diagnostic results (up to 5
    seconds)

 3. if both master and slave pass (assert PDIAG), the master sets bit
    7 of the Error register to zero.

 4. if the master fails, it sets the Error register as below:

 5. if the slave fails, the master will "OR" 80h with the slaves
    status and set the Error register as follows:
      +-------------+---------------------------+
      |ERROR CODE   | DESCRIPTION               |
      +-------------+---------------------------+
      |   01        | no error detected         |
      |   03        | sector buffer error       |
      |   04        | ECC circuitry error       |
      |   05        | control processor error   |
      |   8x        | slave drive failed        |
      +-------------+---------------------------+


 Error Reporting
 ---------------
 When the drive receives a command from the Host, it checks for
 validity of the command, and with the exception of the Initialize
 Drive Parameters command, also checks register values for valid
 range. If the values are invalid, the drive does not execute the
 command, but instead posts the "ERR" bit in the Status register and
 the "ABRT" bit in the Error register.

 If a data error occurs during command execution, the command is
 terminated immediately. Valid errors are listed in the following
 table:

 -----------------+---------------------+---------------------+
 COMMAND          |ERROR REGISTER       |STATUS REGISTER      |
                  +---------------------+---------------------+
                  |BBK|UNC|IDNF|ABRT|TK0|DRDY|DSC|DWF|CORR|ERR|
 -----------------+---+---+----+----+---+----+---+---+----+---+
 Exec. Drive Diag.|   |   |    | V  |   |    |   |   |    | V |
 Format Track     |   |   | V  | V  |   | V  | V | V |    | V |
 Identify Drive   |   |   |    | V  |   | V  | V | V |    | V |
 Initi. Parameters|   |   |    | V  |   |    |   |   |    | V |
 Power Commands   |   |   |    | V  |   |    |   |   |    | V |
 Recalibrate      |   |   |    | V  | V | V  | V | V |    | V |
 Read/Write Buffer|   |   |    | V  |   |    |   |   |    | V |
 Read Long        | V |   | V  | V  |   | V  | V | V |    | V |
 Read Multiple    | V | V | V  | V  |   | V  | V | V | V  | V |
 Read Sectors     | V | V | V  | V  |   | V  | V | V | V  | V |
 Read Verify Sec. | V | V | V  | V  |   | V  | V | V | V  | V |
 Seek             |   |   | V  | V  |   | V  | V | V |    | V |
 Set Multiple     |   |   |    | V  |   | V  | V | V |    | V |
 Write Long       | V |   | V  | V  |   | V  | V | V |    | V |
 Write Multiple   | V |   | V  | V  |   | V  | V | V |    | V |
 Write Sectors    | V |   | V  | V  |   | V  | V | V |    | V |
 Write Verify     | V | V | V  | V  |   | V  | V | V | V  | V |
 -----------------+---+---+----+----+---+----+---+---+----+---+

 Key:
 V     = Valid errors for each command
 ABRT  = Command aborted
 BBK   = Bad block detected
 CORR  = Data error corrected by ECC
 DRDY  = Drive not ready
 DSC   = Disk seek complete not detected
 DWF   = Drive write fault detected
 ERR   = Error detected
 IDNF  = ID mark not found
 TK0   = Track zero not found error
 UNC   = Uncorrectable data error


