0x00     SEEK        Seek request
 0x01     XFR_ALT     Read/Write transfer alternate sector request
 0x02     XFR         Read/Write transfer request
 0x03     RD_CHNL     Access Read Channel request
 0x04     SRV_MEM     Access Servo Memory request
 0x05     SRV_FLW     Add Primary Servo Flaw request
 0x06     DITH        Dithering request
 0x07     DITH_WR     Dithering write enhance request
 0x08     CAL         Drive Calibration request
 0x09     ERA_TRK     Erase Track request
 0x0A     FDB         Execute FDB Motor Leakage Detection test request
 0x0B     FMT_TRK     Format Track request
 0x0C     FMT_SYS     Format System Partition request
 0x0D     FMT_UNT     Format Unit request
 0x0E     HD_RES      Get Head Resistance request
 0x0F     HTR_RES     Get Heater Resistance request
 0x10     GET_RVFF    Get Servo RVFF sensor status
 0x11     ACFF_RECAL  ACFF Recalibrate status
 0x12     TEMP        Get Temperature request
 0x13     TWK_FH      Tweak fly height values request
 0x14     VOLT        Get Voltage Levels request
 0x15     HD_DIAG     Head diagnostics test request
 0x16     HD_SPK      Head Spike Screen request
 0x17     REALLOC     Immediate Reallocation request
 0x18     MRK_PND     Mark Block for Pending Reallocation request
 0x19     HD_FH       Measure Head Fly Heights request
 0x1A     VCM_TEMP    Measure VCM Temperature and Resistance request
 0x1B     MEM_DBG     Memory mapped debug capture request
 0x1C     PROC_DL     Process defect lists request
 0x1D     SCRB_DL     Scrub the defect lists request
 0x1E     PROC_GDL    Process growth defect lists request
 0x1F     REF_SRV_MEM Refresh servo memory request
 0x20     RELD_RAP    Reload RAP parameters request
 0x21     ERR_RATE    Measure error rate
 0x22     DL          Retrieve defect list request
 0x23     SRV_EC      Retrieve the servo error code FIFO request
 0x24     SCN_DFCT    Scan defect adjacent sectors request
 0x25     SELF_SK     Self seek request
 0x26     SK_TUNE     Seek profile tuning request
 0x27     SND_SRV     Send servo request
 0x28     FIX_RAP     Fixup RAP for depop request
 0x29     DEPOP       Send Servo Electrical Depop request
 0x2A     INIT_DITH   Initialize Dithering parameters
 0x2B     PES         Servo PES FIFO access request
 0x2C     PREAMP      Set Preamp mode request
 0x2D     SET_VOLT    Configure voltage margin level request
 0x2E     ZAP         Configure the ZAP correction mode request
 0x2F     SPN_UP      Spinup request
 0x30     SPN_DN      Spindown request
 0x31     ZLR         Track ZLR request
 0x32     UNKNOWN     Unsupported request
 0x33     UNMRK       Unmark Block for Pending Reallocation request
 0x34     TCC         Update TCC Manager request
 0x35     ALT_TONE    Write SMART Alternating Tones Request
 0x36     XFR_TRK     Read/Write transfer track request
 0x37     XFR_WDG     Read/Write transfer wedge request
 0x38     PWR         Set R/W Power Management request
 0x39     CLR_ALT     Clear R/W User Alt List request
 0x3A     LATCH       Put heads on the latch request
 0x3B     SV_ALT      Save R/W User Alt List to Media request
 0x3C     MATLAB      Enter Servo Matlab Shell request
 0x3D     SWEEP       Perform sweep of media to knock off particles request
 0x3E     CLR_SLIP    Clear R/W Slip List request
 0x3F     FA_AFH      Field Adjust AFH request
 0x40     TWK_WR_PWR  Tweak write power request
 0x41     SEC2RLL     Convert sector data to RLL data
 0x42     SWD         SWD(Skip Write Detect) Enable/Disable request
 0x43     CLR_ALT_ENT Clear User Alt List Entry request
 0x44     ADJ_CLR     Adjust Target Clearance request
 0x45     FALL        Control drive free-fall protection request
 0x46     XFR_SEC     Read/Write transfer sector request
 0x47     DISC_SLIP   Update servo disc slip parameters request
 0x48     RE_ALT      Restore R/W User Alt List from Media request
 0x49     RST_RVFF    Reset Servo RVFF sensor status request
 0x4A     HST         Head Stability Test
 0x4B     PREP_DL     Prepare servo for download request
 0x4C     CLR_SD      Clear R/W Servo Defect List request
 0x4D     HD_ASYM     Measure Head Asymmetry request
 0x4E     SET_FAST_IO Setup Fast IO request
 0x4F     PZT_CAL     PZT Calibration request
 0x50     CHANNEL_FREQUENCY_REDUCE Channel Frequency Reduce request
 0x51     UPDATE_DATA_SCRUB_LIST Update Data Srub List request
 0x52     EBMS_CAL      EBMS Calibration request
 0x53     HTR_CTRL    Heater Control request
 0x54     CHNL_MEM    Access Channel Memory request
 0x55     EFD         EFD(EBMS Fault Detect) Enable/Disable request
 0x55     EFD         Reserved for EFD(EBMS Fault Detect) Enable/Disable request