22 Dec
2006
22 Dec
'06
2:06 p.m.
Haven't seen any analogue hard disk drives
recently...
I have, I own one...
It's a single-platter, multiple fixed head unit. The control electronics
causes it to rotate (mains motor with disk+coil eddg current brake) at
one revolution per video frame time, and video is stored on the disk
using FM analuge recording (like the recording method used in a VCR). Of
course it plays pack 3 trakcs simulateously to give colour (RGB) output.
The verison I have is called a PPL 121 graphics system for the PDP11, and
includes an FM modulator and contorl electronics that links to a DR11-B
interface. I am told the technology originated in the 'action replay'
recorders used on television.
-tony