+/* hpcs1 */
+#define HP_SC 0100000 /* special condition */
+#define HP_TRE 0040000 /* transfer error */
+#define HP_DVA 0004000 /* drive available */
+#define HP_RDY 0000200 /* controller ready */
+#define HP_IE 0000100 /* interrupt enable */
+/* bits 5-1 are the command */
+#define HP_GO 0000001
+
+/* commands */
+#define HP_NOP 000 /* no operation */
+#define HP_UNLOAD 002 /* offline drive */
+#define HP_SEEK 004 /* seek */
+#define HP_RECAL 006 /* recalibrate */
+#define HP_DCLR 010 /* drive clear */
+#define HP_RELEASE 012 /* release */
+#define HP_OFFSET 014 /* offset */
+#define HP_RTC 016 /* return to centerline */
+#define HP_PRESET 020 /* read-in preset */
+#define HP_PACK 022 /* pack acknowledge */
+#define HP_SEARCH 030 /* search */
+#define HP_DIAGNOSE 034 /* diagnose drive */
+#define HP_WCDATA 050 /* write check data */
+#define HP_WCHDR 052 /* write check header and data */
+#define HP_WCOM 060 /* write data */
+#define HP_WHDR 062 /* write header */
+#define HP_WTRACKD 064 /* write track descriptor */
+#define HP_RCOM 070 /* read data */
+#define HP_RHDR 072 /* read header and data */
+#define HP_RTRACKD 074 /* read track descriptor */
+
+/* hpds */
+#define HPDS_ATA 0100000 /* attention active */
+#define HPDS_ERR 0040000 /* composite drive error */
+#define HPDS_PIP 0020000 /* positioning in progress */
+#define HPDS_MOL 0010000 /* medium on line */
+#define HPDS_WRL 0004000 /* write locked */
+#define HPDS_LST 0002000 /* last sector transferred */
+#define HPDS_PGM 0001000 /* programmable */
+#define HPDS_DPR 0000400 /* drive present */
+#define HPDS_DRY 0000200 /* drive ready */
+#define HPDS_VV 0000100 /* volume valid */
+/* bits 1-5 are spare */
+#define HPDS_OM 0000001 /* offset mode */
+
+#define HPDS_DREADY (HPDS_DPR|HPDS_DRY|HPDS_MOL|HPDS_VV)
+#define HPDS_BITS \
+"\10\20ATA\17ERR\16PIP\15MOL\14WRL\13LST\12PGM\11DPR\10DRY\7VV\1OM"
+
+/* hper1 */
+#define HPER1_DCK 0100000 /* data check */
+#define HPER1_UNS 0040000 /* drive unsafe */
+#define HPER1_OPI 0020000 /* operation incomplete */
+#define HPER1_DTE 0010000 /* drive timing error */
+#define HPER1_WLE 0004000 /* write lock error */
+#define HPER1_IAE 0002000 /* invalid address error */
+#define HPER1_AOE 0001000 /* address overflow error */
+#define HPER1_HCRC 0000400 /* header crc error */
+#define HPER1_HCE 0000200 /* header compare error */
+#define HPER1_ECH 0000100 /* ecc hard error */
+#define HPER1_WCF 0000040 /* write clock fail */
+#define HPER1_FER 0000020 /* format error */
+#define HPER1_PAR 0000010 /* parity error */
+#define HPER1_RMR 0000004 /* register modification refused */
+#define HPER1_ILR 0000002 /* illegal register */
+#define HPER1_ILF 0000001 /* illegal function */
+
+#define HPER1_BITS \
+"\10\20DCK\17UNS\16OPI\15DTE\14WLE\13IAE\12AOE\11HCRC\10HCE\
+\7ECH\6WCF\5FER\4PAR\3RMR\2ILR\1ILF"
+#define HPER1_HARD \
+ (HPER1_WLE|HPER1_IAE|HPER1_AOE|\
+ HPER1_FER|HPER1_RMR|HPER1_ILR|HPER1_ILF)
+
+/* hper2 */
+#define HPER2_BSE 0100000 /* bad sector error */
+#define HPER2_SKI 0040000 /* seek incomplete */
+#define HPER2_OPE 0020000 /* operator plug error */
+#define HPER2_IVC 0010000 /* invalid command */
+#define HPER2_LSC 0004000 /* loss of system clock */
+#define HPER2_LBC 0002000 /* loss of bit check */
+#define HPER2_DVC 0000200 /* device check */
+#define HPER2_SSE 0000040 /* skip sector error (rm80) */
+#define HPER2_DPE 0000010 /* data parity error */
+
+#define HPER2_BITS \
+"\10\20BSE\17SKI\16OPE\15IVC\14LSC\13LBC\10DVC\5SSE\4DPE"
+#define HPER2_HARD (HPER2_OPE)
+
+/* hpof */
+#define HPOF_CMO 0100000 /* command modifier */
+#define HPOF_MTD 0040000 /* move track descriptor */
+#define HPOF_FMT22 0010000 /* 16 bit format */
+#define HPOF_ECI 0004000 /* ecc inhibit */
+#define HPOF_HCI 0002000 /* header compare inhibit */
+#define HPOF_SSEI 0001000 /* skip sector inhibit */
+
+#define HPOF_P400 020 /* +400 uinches */
+#define HPOF_M400 0220 /* -400 uinches */
+#define HPOF_P800 040 /* +800 uinches */
+#define HPOF_M800 0240 /* -800 uinches */
+#define HPOF_P1200 060 /* +1200 uinches */
+#define HPOF_M1200 0260 /* -1200 uinches */