RS64 disk drive
|Manufacturer:||Digital Equipment Corporation|
|Drive Controller(s):||RC11 (UNIBUS)|
|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|
|Tracks Per Surface:||32|
|Sectors Per Track:||64|
|Words Per Sector:||32|
|Density:||1700 bpi (maximum)|
|Physical Size:||10" (high), 19" (W, D)|
|Power Consumption:||6A (starting), 2.2A (operating)|
The RS64 is a fixed-platter fixed-head disk drive used on PDP-8's and early PDP-11s. 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).