A plated disk, which consists of a chemically plated Co-Ni-P medium and a newly developed and spin-coated overcoat, was prepared using techniques based on extensive studies on error defects throughout the production process. Plated disk 787 BPM/40 TPM feasibility was experimentally evaluated. Read/write characteristics and total phase shift were measured with a 15µm track width Mn-Zn ferrite head at a 787 BPM linear density. The numbers of errors were measured with 30 µm track width heads at 350 BPM and 635 BPM linear densities. Wear durability was determined for 30,000 contact start/stop (CSS) cycle tests with IBM-3340 compatible and narrower track width heads. From the results, it was concluded that the 787 BPM/40 TPM recording density can be accomplished with the plated disk and a conventional narrow track width Mn-Zn ferrite head. © 1979 IEEE
