+#define i_fs i_un.ui_fs
+#define i_bus i_adapt
+
+/* codes for sector header word 1 */
+#define HDR1_FMT22 0x1000 /* standard 16 bit format */
+#define HDR1_OKSCT 0xc000 /* sector ok */
+#define HDR1_SSF 0x2000 /* skip sector flag */
+
+#define F_READ 0x0001 /* file opened for reading */
+#define F_WRITE 0x0002 /* file opened for writing */
+#define F_ALLOC 0x0004 /* buffer allocated */
+#define F_FILE 0x0008 /* file instead of device */
+#define F_NBSF 0x0010 /* no bad sector forwarding */
+#define F_ECCLM 0x0020 /* limit # of bits in ecc correction */
+#define F_SSI 0x0040 /* set skip sector inhibit */
+#define F_SEVRE 0x0080 /* Severe burnin (no retries, no ECC) */
+
+/* io types */
+#define F_RDDATA 0x0100 /* read data */
+#define F_WRDATA 0x0200 /* write data */
+#define F_HDR 0x0400 /* include header on next i/o */
+#define F_CHECK 0x0800 /* perform check of data read/write */
+#define F_HCHECK 0x1000 /* perform check of header and data */
+
+#define F_TYPEMASK 0xff00
+
+#define READ F_READ
+#define WRITE F_WRITE
+
+/*
+ * Lseek call.
+ */
+#define L_SET 0 /* absolute offset */