RK05 disk drive
| RK05 | |
| Manufacturer: | Digital Equipment Corporation |
|---|---|
| Drive Controller(s): | RK8E (Omnibus) RK11-D (UNIBUS) RKV11-D (QBUS) |
| Capacity: | 2.45 Mbytes (most versions) |
| Transfer Rate: | 102 Kword/sec (RK8E) 90.1 Kword/sec (RK11) |
| Revolutions per Minute: | 1500 |
| Total Surfaces: | 2 |
| Words per Sector: | 256 |
| Tracks per Inch: | 100 |
| Density: | 2200 bpi |
| Recording Method: | Double Frequency NRZ |
The RK05 was moving-head magnetic disk drive, most versions of which used removable packs, designed and manufactured by DEC. It was based on, but not completely compatible with, the earlier RK02 and RK03 drives (which were sold by DEC, but not manufactured by them), which in turn were inspired by the IBM 2315 drive and pack.
The pack contained a platter 14 inches in diameter, coated with iron oxide. Since the disk was hard sectored, platters used in the PDP-8 were physically incompatible with those used in the PDP-11, although the drives themselves were completely identical for both.
The controller interface on the RK05 was mostly compatible with the earlier RK02/RK03, although it used a different 'drive select' mechanism, which allowed an RK11-D controller to support up to 8 RK05 drives on a single drive bus, as opposed to only 4 per bus with the earlier RK02/03 and RK11-C. The packs were compatible.
RK05 models
- RK05E - a version which contained many reliability enhancements
- RK05J - the final version
- RK05F - a version using a permanently installed platter, which allowed it to operate at twice the track density of the standard RK05, doubling the capacity of the drive; a single RK05F emulated two normal RK05 drives
Other specifications
- Data tracks - 203 (nominally 200 plus 3 spares; many systems used all 203, as reliability was high)
- Average access time - 70 msec
- Time for 1/2 revolution - 20 msec
- One track seek - 10 msec
- Average seek - 50 msec
- Maximum seek - 85 msec
- Physical size - 19" W x 10.5" H x 26.5" L
- Weight - 110 pounds
- Power consumption - 230 VA (running); 1150 VA (starting, 2 sec)
