INT 4B - Common Access Method SCSI interface (draft revision 1.9)
        ES:DI -> CAM Control Block (see INT 4F/AX=8100h)
Notes:  the CAM committee moved the interface to INT 4F after revision 1.9
          to avoid conflicting with the IBM SCSI interface and the Virtual
          DMA specification
        the installation check for the driver is the string "SCSI_CAM" eight
          bytes past the INT 4Bh handler
        it is not known whether any drivers actually implemented this
          interface on INT 4B instead of INT 4F