Abstract: A magnetic disk drive unit or machine adapted to receive disk-jacket assemblies for magnetically reading from and writing on a disk in such an assembly. The jacket of the assembly is made of a material with high electrical resistance which accumulates static electricity through usual handling. The machine includes a skirt having an electrically conducting layer thereon and hung on an upper portion of the machine so that the skirt is in contact with an outer surface of the jacket for draining off an electrostatic charge accumulation on the jacket very quickly.

Abstract: A rotary magnetic record disk assembly comprising a magnetic disk which is rotatably disposed within a containing jacket of material of high electrically insulating characteristics. An electrically conductive layer is disposed on the inside surface of the jacket for draining away electrostatic charge on the jacket.