Disk platter identification

Ethan> On 7/19/05, Director <csmuseum at cse.uta.edu> wrote: Ethan> At 1/4" thick, there's a chance it's a DF32 platter. I don't Ethan> remember how large the hub hole is, but at first glance, and Ethan> with the PDP-8 suggestion, that's what I'd have to guess. Ethan> I have never seen an RF08 platter, so I don't know how Ethan> physically similar they are. Is the RF08 like the RF11? On second thought, that may be more like it. I forgot the size of the RF64, but I don't think it was 16 inches diameter. (I though 8 inches was diameter not radius...) For the RF11 that sounds just right. I haven't ever seen an RS03 or RS04 platter; that's probably about the same size as the RF11. I don't think the RF11 had a ritation sensor. It had a clock/timing track which encoded, among other things, the start of track mark. There was a gap at that point. When reformatting the timing track (if you replaced the platter, for example) you'd adjust a knob on the timing track formatter until its indicator lights showed that the gap length was within the required range. paul