Availability:
     Level 2    , 'V'

  Quick Help:
     Read Verify CHS, V[Sec],[NumSecs],[CompareBlk],[Opts]

  Description:
    This command reads data from the disk starting at the specified sector on the target
    track for the specified number of sectors.  The data is read into the Diagnostic Read
    Buffer and is compared to the data contained in the specified buffer.

  Input Parameters:

     0 - Logical or Physical Sector Address.
    
         If Parameter 3 bit 5 is set, this parameter contains the physical sector address
         of the first sector to read, else this parameter contains the User Area logical
         sector address of the first sector to read.
    
           Type:    Unsigned 16-bit value
    
           Range:   0 to maximum logical or physical sector address on the target track
    
           Default: 0
    
     1 - Transfer Length.
    
         This parameter specifies the number of consecutive sectors to read.
    
           Type:    Unsigned 32-bit value
    
           Range:   0 to 0xFFFFFFFF
    
           Default: If the Sector Address was entered and the Transfer Length was not entered,
                    then only the specified sector will be read.
    
                    If both the Sector Address and Transfer Length are not entered, then the
                    Transfer Length will be set based on the Test Space that is selected.
                    If the Random Transfer Length option is selected, a random value will be
                    used that is less than or equal to the number of sectors remaining on the
                    track.  If the Random Transfer Length option is not selected, the number
                    of sectors remaining on the track will be read.
    
                    If a Transfer Length is entered, it will be limited to the number of
                    sectors remaining on the track.
    
    
     2 - Compare Buffer Block Number.
    
         This parameter specifies the number of the buffer block that contains the data to be
         compared to the data that is read.
    
           Type:    Unsigned 16-bit value
    
           Range:   0 to 0xFFFF
    
           Default: If a Compare Buffer Block Number is not specified, the data read will be
                    compared to the data contained in the Diagnostic Write Buffer.
    
    
     3 - Options.
    
         This parameter is a bit-significant value that allows the user to select the
         following options.
    
           Bits 15-6:  not used.
    
           Bit 5:      Read and Verify Physical Sectors.
    
                       If this bit is set, Parameter 0 specifies a physical sector address,
                       else it specifies a User Area logical sector address.
    
           Bit 4:      Read All Test Space Sectors.
    
                       If this bit is set, all of the sectors in the Test Space will be
                       read, else only the System Area Sectors specified by Parameters 0
                       and 1 will be read.
    
           Bit 3:      not used.
     
           Bit 2:      Rotate Buffer Sector Offset.
     
                       If this bit is set, the Target Buffer Sector Offset will be rotated
                       by 1 prior to the execution of this diagnostic command.
                       This bit was originally added to help writing random data pattern
                       reduce execution time by not having to re-fill the diagnostic buffer
                       with new random data pattern, which takes great amount of time,
                       but just rotating the Target Buffer Sector Offset at every time this
                       diagnostic command is executed with this option set.
                       To see or change the current Targer Buffer Sector Offset, please refer
                       all Level 'A', Set Test Space, diagnostic command for detail how-to.
    
    
           Bit 1:      Enable Dynamic Sparing.
    
                       If this bit is set, sectors containing media defects that meet
                       the failure criteria will be spared.
    
    
           Bit 0:      Continue On Error.
     
                       If this bit is set and an error occurs, the read operation will
                       continue and attempt to read all of the requested sectors.  Each
                       error encountered will be displayed.
    
           Type:    Unsigned 16-bit value
    
           Range:   0 to 0xFFFF
    
           Default: 0    (Read and Verify Logical User Area Sectors,
                          Read the requested sectors,
                          Disable Dynamic Sparing,
                          Stop On Error)
    
  Output Data:

    If an error occurred, the following information will be displayed.
    
          "DiagError aaaaaaaa R/W Status c R/W Error dddddddd"
    
       and
    
          "Next User LBA eeeeeeee LLL CHS ffffff.g.hhhh PLP CHS iiiiii.j.kkkk"
          "Remaining Transfer Length llllllll"
    
       or
    
          "Next System LBA eeeeeeee LLL CHS ffffff.g.hhhh PLP CHS iiiiii.j.kkkk"
          "Remaining Transfer Length llllllll"
    
       where
    
          aaaaaaaa is the Diagnostic Error Code
    
          c is the status returned by the R/W subsystem
    
                0 = R/W request completed successfully with error recovery
                1 = R/W request completed successfully (no error recovery performed)
                2 = R/W request failed
    
          dddddddd is the error code returned by the R/W subsystem
    
          eeeeeeee is the Disk Logical Block Address of the sector in error
    
          ffffff is the Logical Cylinder Address of the sector in error
    
          g is the Logical Head Address of the sector in error
    
          hhhh is the Logical Sector Address of the sector in error
    
          iiiiii is the Physical Cylinder Address of the sector in error
    
          j is the Logical Head Address of the sector in error
    
          kkkk is the Physical Sector Address of the sector in error
    
          llllllll is the number of sectors remaining to be read or written
    
    If the Verbose Formatted ASCII Data Output Mode is selected, the Verbose Mode option
    bits will enable the following data to be output when set.
    
       Bit 0:      Enables the R/W Status and R/W Error to be displayed
       Bit 1:      Enable the Next Address to be displayed
       Bit 2:      Enables the Track Position and Track Follow Offset to be displayed
       Bit 3:      Enables the Target Address to be displayed
       Bit 4:      Enables the Recovery Status to be displayed
       Bit 5:      Enables the Fault Status to be displayed
       Bit 6:      Enables the Elapsed Time to be displayed
       Bits 31-7:  NA
    
    If Bit 0 is set, the R/W Status and R/W Error will be displayed even if no error
    occurred.  The data displayed will be formatted as shown above.
    
    If Bit 1 is set, the Next Address will be displayed even if no error occurred.  The
    data displayed will be formatted as shown above.
    
    If Bit 2 is set, the Track Position and Track Follow Offset will be displayed as
    follows.
    
          "Read Position, Persistent Offset m.m% Total Offset n.n%"          or
          "Write Position, Persistent Offset m.m% Total Offset n.n%"         or
          "Write Header Position, Persistent Offset m.m% Total Offset n.n%"
    
       where
    
          m.m is the Persistent Track Follow Offset in units of percentage of track width
    
          n.n is the Total Track Follow Offset in units of percentage of track width
    
    If Bit 3 is set, the Target Address will be displayed as follows.
    
          "Target User LBA pppppppp LLL CHS qqqqqq.r.ssss PLP CHS tttttt.u.vvvv"
          "Starting Transfer Length wwwwwwww"
    
       or
    
          "Target System LBA pppppppp LLL CHS qqqqqq.r.ssss PLP CHS tttttt.u.vvvv"
          "Starting Transfer Length wwwwwwww"
    
       where
    
          pppppppp is the starting Disk Logical Block Address
    
          qqqqqq is the starting Logical Cylinder Address
    
          r is the starting Logical Head Address
    
          ssss is the starting Logical Sector Address
    
          tttttt is the starting Physical Cylinder Address
    
          u is the starting Logical Head Address
    
          vvvv is the starting Physical Sector Address
    
          wwwwwwww is the starting Transfer Length
    
    If Bit 4 is set, the Recovery Status will be displayed as follows.
    
          "Recovered User LBA AAAAAAAA LLL CHS BBBBBB.C.DDDD PLP CHS EEEEEE.F.GGGG"
          "Recovery Flags HHHH Count II"
    
       or
    
          "Recovered System LBA AAAAAAAA LLL CHS BBBBBB.C.DDDD PLP CHS EEEEEE.F.GGGG"
          "Recovery Flags HHHH Count II"
    
       where
    
          AAAAAAAA is the Disk Logical Block Address of the last recovered sector
    
          BBBBBB is the Logical Cylinder Address of the last recovered sector
    
          C is the Logical Head Address of the last recovered sector
    
          DDDD is the Logical Sector Address of the last recovered sector
    
          EEEEEE is the Physical Cylinder Address of the last recovered sector
    
          F is the Logical Head Address of the last recovered sector
    
          GGGG is the Physical Sector Address of the last recovered sector
    
          HHHH are the Recovery Flags reported by the Read/Write code
    
          II is the Recovery Count reported by the Read/Write code
    
    If Bit 5 is set, the Fault Status will be displayed as follows.
    
          "Drive Fault Status JJJJ Preamp Fault Status KKKK"
          "Read Channel Faults:
           SRC Fault Reg 190 = aaaa
           SRC Fault Reg 191 = bbbb
           SID Reg 20B = cccc
           SID Reg 26C = dddd
           SID Reg 26F = eeee
           SID Reg 251 = fffff
    
       where
    
          JJJJ is the Drive Fault Status reported by the Read/Write code
    
          KKKK is the Preamp Fault Status reported by the Read/Write code
    
          aaaa  is the SRC channel fault Register 190h value
    
          bbbb is the SRC channel fault register 191h value
    
          cccc is the SID channel fault register 20bh   value
    
          dddd is the SID channel fault reg 26ch   value
    
          eeee is the SID Channel fault reg 251h value
    
    If Bit 6 is set, the Elapsed Time for the read/write operation will be displayed.

    
       "Elapsed Time a mins b secs"  or
       "Elapsed Time b.c secs"       or
       "Elapsed Time c.d msecs"
    
    where
    
       a is minutes
       b is seconds
       c is milliseconds
       d is microseconds
    
    or



    If an error occurred, the following information will be displayed.
    
          "DiagError aaaaaaaa"
    
       where
    
          aaaaaaaa is the Diagnostic Error Code
    
    If a data miscompare was detected during a read compare operation, the following
    information will be displayed.
    
          "DiagError aaaaaaaa"
    
       followed by
    
          "User LBA cccccccc LLL CHS dddddd.e.ffff PLP CHS gggggg.h.iiii"
          "Byte Offset = jjjj Expected = kk Actual = ll"
    
       or
    
          "System LBA cccccccc LLL CHS dddddd.e.ffff PLP CHS gggggg.h.iiii"
          "Byte Offset = jjjj Expected = kk Actual = ll"
    
       where
    
          aaaaaaaa is the Diagnostic Error Code
    
          cccccccc is the Disk Logical Block Address of the sector that miscompared
    
          dddddd   is the Logical Cylinder Address of the sector that miscompared
    
          e        is the Logical Head Address of the sector that miscompared
    
          ffff     is the Logical Sector Address of the sector that miscompared
    
          gggggg   is the Physical Cylinder Address of the sector that miscompared
    
          h        is the Logical Head Address of the sector that miscompared
    
          iiii     is the Physical Sector Address of the sector that miscompared
    
          jjjj     is the byte offset from the start of the sector to the byte that miscompared
    
          kk       is the expected byte value
    
          ll       is the actual byte value
    
  Examples:
    Example #1:
       To read and verify a single logical sector
       (in this case logical sector 23 on logical cylinder 45 head 1)

          F3 2>A0
          F3 2>S45,1
          F3 2>V23

    Example #2:
       To read and verify multiple logical sectors
       (in this case logical sectors 23 to 26 on logical cylinder 45 head 1)

          F3 2>A0
          F3 2>S45,1
          F3 2>V23,4

    Example #3:
       To read and verify all of the logical sectors on a track
       (in this case all logical sectors on logical cylinder 45 head 1)

          F3 2>A0
          F3 2>S45,1
          F3 2>V

    Example #4:
       To read and verify all of the logical sectors on multiple tracks
       (in this case all logical sectors on logical cylinders 45 to 49 head 0)

       Note: You must seek to the track before the first one to be read.

          F3 2>A3
          F3 2>S44,0
          F3 2>L,5
          F3 2>V

    Example #5:
       To read and verify all of the logical sectors on a track and continue on error
       (in this case all logical sectors on logical cylinder 45 head 0)

       Note: An error message will be displayed for each sector in error.

          F3 2>A0
          F3 2>S45,0
          F3 2>V,,,1

    Example #6:
       To read and verify all of the logical sectors in the test space and continue on error

       Note: The Test Space is selected by the all level 'A' command.  An error
       message will be displayed for each sector in error.

          F3 2>V,,,11

    Example #7:
       To read and verify a single physical sector
       (in this case physical sector 32 on physical cylinder 54 head 0)

          F3 2>A0
          F3 2>s54,0,22
          F3 2>V32,,,20

    Example #8:
       To read and verify multiple physical sectors
       (in this case physical sectors 32 to 35 on physical cylinder 54 head 0)

          F3 2>A0
          F3 2>s54,0,22
          F3 2>V32,4,,20

    Example #9:
       To read and verify all of the physical sectors on a track
       (in this case all physical sectors on physical cylinder 54 head 0)

          F3 2>A0
          F3 2>s54,0,22
          F3 2>V,,,20

    Example #10:
       To read a single logical sector to a specific sector offset in the diagnostic read
       buffer, then compare the data at the sector offset in the diagnostic read buffer
       against the data at the same sector offset in the diagnostic write buffer to verity
       the data
       (in this case logical sector 23 on logical cylinder 45 head 1,
        to the sector offset of 5 in the diagnostic read buffer)

          F3 2>A0
          F3 2>AF,5
          F3 2>S45,1
          F3 2>V23

    Example #11:
       To rotate the buffer sector offset by 1 and read a single logical sector to the
       rotated sector offset in the diagnostic read buffer, then compare the data at the
       sector offset in the diagnostic read buffer against the data at the same sector offset
       in the diagnostic write buffer to verity the data
       (This example assumes user ran the Example #10 above right before this example,
        in this case logical sector 24 on logical cylinder 45 head 1,
        to the sector offset of 6 in the diagnostic read buffer)

          F3 2>V24,,,4

  Revision History:

    0001.0000   Initial revision.
    0001.0001   Eliminated the Enable ZAP Updates and Enable Track Skipping option.
    0001.0002   Added new Rotate Buffer Sector Offset option to the bit 2 of the parameter 3.
    0011.0000   Combined the PSG Diagnostic Error Codes (PSGDEC) and the Diagnostic External
                Test Service Error Codes (DETSEC) into a single set of Diagnostic Error Codes
                (DiagError).