RC25 disk drive
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| RC25 | |
| Manufacturer: | DEC | 
|---|---|
| Drive Controller(s): | KLESI Low-End Storage Interconnect | 
| Capacity: |  26 Mbytes (fixed) 26 Mbytes (removeable)  | 
| Transfer Rate: | 1.25 Mbytes/sec | 
| Average Access Time: | 30.5-45.5 msec | 
| Revolutions per Minute: | 2850 | 
| 1/2 Revolution Time: | 10.5 msec | 
| Average Seek Time: | 20-35 msec | 
| Maximum Seek Time: | 55 msec | 
| Media: |  1 fixed 1 removeable  | 
| Total Surfaces: | 4 (2 fixed, 2 removeable) | 
| Number of Heads: | 4 | 
| Tracks per Surface: | 821 | 
| Sectors per Track: | 31 | 
| Bytes per Sector: | 512 | 
| Tracks per Inch: | 1,000 | 
| Density: | 12,350 bits/inch | 
| Start Time: | 60 secs (max) | 
| Stop Time: | 30 secs (max) | 
| Physical Size: | 10.4" x 19.9" x 22.1" | 
| Weight: | 65 lbs (single drive) | 
| Power Consumption: | 300 watts (idle) | 
The RC25 disk drive was a combination non-removable-media disk and removable-pack disk (using a sealed pack) on a singled spindle, from DEC. Each 8" platter had a capacity of 25 MB, for a total of 52 MB. It connected to the device controller via the DEC standard LESI bus; a second 'slave' drive can be connected to the first 'master' drive. It uses the Mass Storage Control Protocol, and is member of the Digital Storage Architecture.
External links
- rc25 - documentation at Bitsavers
 - RC25 Disk Subsystem
 - RC25 Disk Subsystem Pocket Service Guide (EK-0RC25-PS-002)