Photo: Red Hill.
Microscience was a high-cost, small-volume maker of quality hard drives back in the days when you didn't have to be a multinational giant to afford hard drive research and development. They made a range of beautifully crafted 5.25 inch voice-coil drives, all with a distinctive rippled top. The HH-1050 was the smallest and most common of them, and very fast for its day.
Notice the odd number of heads: voice-coil drives need to have positioning information encoded onto the drive itself, so that the heads can find the correct track. (Stepper drives just step in or out the required number of times and hope for the best.) Until the development of embedded servo technology around teh end of the 1980s, all voice-coil drives had to sacrifice one complete surface for head positioning — you couldn't put data on the servo tracks. This meant that it was uneconomic to make small voice-coil drives: in a single-platter drive, you'd waste 50%, but in a big 4-platter drive, you only waste 12.5%. Notice that a few new drives still did this until about 1995.
|Data rate||7.5 Mbit/sec||Spin rate||3600 RPM|
|Seek time||28ms||Actuator||Voice coil|
|AT drive type||2||Form||3.5" half-height|
|HH-1050||42MB||5 thin-film heads||1987|