RS64 disk drive
From Computer History Wiki
| RS64 | |
| Manufacturer: | Digital Equipment Corporation |
|---|---|
| Drive Controller(s): | RC11 (UNIBUS) |
| Capacity: | 128KB |
| Transfer Rate: | 125KB/sec (60 Hz), 100KB/sec (50 Hz) |
| Average Access Time: | 16.9msec (60Hz), 20.3msec (50Hz) |
| Revolutions per Minute: | ~1800 (60Hz), ~1400 (50Hz) |
| Media: | 10" diameter nickel-cobalt plated surface with proprietary protective coating |
| Total Surfaces: | 1 |
| Tracks per Surface: | 32 |
| Sectors per Track: | 64 |
| Words per Sector: | 32 |
| Density: | 1700 bpi (maximum) |
| Recording Method: | NRZI |
| Physical Size: | 10" (high), 19" (W, D) |
| Weight: | 64 lbs |
| Power Consumption: | 6A (starting), 2.2A (operating) |
The RS64 is a fixed-platter fixed-head disk drive used on early PDP-11s. (No PDP-8 or other early DEC system device controller has yet been seen for it, although the look of its Service Manual dates it to just before the early -11's.) It could store up to 128KB of data in 64 byte blocks. It used 32 fixed read/write heads for data, and 6 heads to read timing/address tracks (in two duplicated sets of 3, for reliability; switch-over from one set to another was manual).
A special device had to be used to write the timing/address tracks. The drive had the ability to write-protect tracks 0-N ('N' set in switches).
