RL01/02 disk drive
From Computer History Wiki
| RL01 | |
| Manufacturer: | Digital Equipment Corporation |
|---|---|
| Drive Controller(s): | RL11 (UNIBUS) |
| Capacity: | 5.2 Mbytes (formatted) |
| Transfer Rate: | 512 Kbytes/sec 3.9 usec/word (peak) |
| Average Access Time: | 67.5 msec |
| Revolutions per Minute: | 2400 |
| 1/2 Revolution Time: | 12.5 msec |
| One Track Seek Time: | 15 msec |
| Average Seek Time: | 55 msec |
| Maximum Seek Time: | 100 msec |
| Head Switching Time: | 8 msec (maximum) |
| Total Surfaces: | 2 |
| Tracks per Surface: | 256 |
| Sectors per Track: | 40 |
| Words per Sector: | 128 |
| Tracks per Inch: | 125 |
| Density: | 3725 bpi (maximum) |
| Recording Method: | Modified Frequency Modulation (MFM) |
| Start Time: | 40 seconds |
| Stop Time: | 30 seconds |
| Physical Size: | 19" W x 10-1/2" H x 25" L |
| Weight: | 55 pounds |
| Power Consumption: | 160W (running); 550 VA (starting) |
The RL01 is a 5MiB, single platter, removable pack disk drive introduced in 1976 by Digital Equipment Corporation. It used an IBM 5440 type pack, as used on the IBM System/3.
To keep the heads properly aligned on the tracks, it used a servo system driven by servo data written on the pack (along with sector headers) at the factory; packs cannnot be low-level re-formatted in the field.
Early versions of the drive included a set of brushes that swing out over the platter on start-up; these were deleted in later versions.
The QBUS controllers are the RLV11 and RLV12, the latter being the Q22 version.
The RL02 is a higher density version, with twice as many tracks.
