On Wed, 8 Jul 2026, steve shumaker via cctalk wrote:
I recently stumbled across a early hard drive platter that appears, based on measurements, to be an original RAMAC platter. Very little comes up in Google beyond basic measures (diameter of 24" and a head motion of 6".) I'm curious if there was anything out there that had similar measurements. I did find a photo on facebook but it clearly has different measurements. Platter is in poor condition (no oxide, nicks and dings, etc although still obviously a platter) but the owner is fascinated with possible origin.
IFF there are any similar 24 inch platters, they are likely to have different hubs. Does yours have a seven and a half inch center hole? Ramac had a metal inner hub that clamped to that. There could also be subtle differences in substrata thickness, chemistry of the rust, etc.
