18 Feb
2018
18 Feb
'18
10:46 a.m.
The claim about the "only CDC disk drive with
hydraulic positioner"? is
false.? Starting with the Bryant 6603, I believe that the 808 and very
rare 821 also used hydraulics.? Voice-coil positioners started to be
used with the 844 drives.? I don't recall what the 854 used, as it
wasn't very common on big CDC iron.
--Chuck
Chuck, thanks a lot for your reply and for these insights! I indeed
wasn't aware that within CDC, the 808 and 821 worked-with hydraulics, too. I will
update the description on the web accordingly!The 85x drives don't use a hydraulic
positioner. To my understanding, they used a solenoid and a carriage assembly that is
controlled by a photo-cell, -transistor and a timing wheel with slots.
All the best,Pierre