+/*
+ * Per-device structure
+ * (one for each RM/RP disk, and one for each tape formatter).
+ *
+ * This structure is used by the device driver as its argument
+ * to the massbus driver, and by the massbus driver to locate
+ * the device driver for a particular massbus slot.
+ *
+ * The device drivers hang ready buffers on this structure,
+ * and the massbus driver will start i/o on the first such buffer
+ * when appropriate.
+ */
+struct mba_device {
+ struct mba_driver *mi_driver;
+ short mi_unit; /* unit number to the system */
+ short mi_mbanum; /* the mba it is on */
+ short mi_drive; /* controller on mba */
+ short mi_dk; /* driver number for iostat */
+ short mi_alive; /* device exists */
+ short mi_type; /* driver specific unit type */
+ struct buf mi_tab; /* head of queue for this device */
+ struct mba_device *mi_forw;
+/* we could compute these every time, but hereby save time */
+ struct mba_regs *mi_mba;
+ struct mba_drv *mi_drv;
+ struct mba_hd *mi_hd;
+};