RA60 Disk Drive
| RA60 | |
| Manufacturer: | Digital Equipment Corporation |
|---|---|
| Year Introduced: | June, 1982 |
| Drive Controller(s): | all SDI controllers |
| Capacity: | 205 Mbytes (16-bit mode, formatted) 208 Mbytes (18-bit mode, formatted) |
| Transfer Rate: | 1.3 Mbytes/sec |
| Average Access Time: | 50.3 msec |
| Revolutions per Minute: | 3600 |
| 1/2 Revolution Time: | 8.3 msec |
| One Track Seek Time: | 6.7 msec |
| Average Seek Time: | 41.7 msec |
| Maximum Seek Time: | 75 msec |
| Total Surfaces: | 6 |
| Number of Heads: | 6 |
| Tracks per Surface: | 1,588 |
| Sectors per Track: | 38 (18-bit word mode) 42 (16-bit word mode) |
| Bytes per Sector: | 512 (16-bit word mode) 576 (16-bit word mode) |
| Tracks per Inch: | 779 |
| Density: | 9,668 |
| Start Time: | 60 secs (max) |
| Stop Time: | 40 secs (max) |
| Physical Size: | 26cm x 44cm x 85cm |
| Weight: | 155 lbs (approx) |
| Power Consumption: | 780 watts |
The RA60 Disk Drive is a DEC SDI removable-pack disk drive, introduced in 1982; it could support either 16- or 18-bit words. It is the only removable-media drive in the RAxx group of drives; the others (RA70, etc) are all non-removable-media disk drives. It is member of the Digital Storage Architecture family.
It uses the RA60-P pack, which has a five platters, with six data surfaces; the two end platters are purely protective. Track servo information is pre-recorded on the data surfaces; the servo information is recorded at manufacturing time.
The RA60 can also be connected in a dual-port arrangement, permitting its use by two controllers.
Quote from the combined DEC RA60/RA80/RA81 1982 sales brochure:
The RA60 is the industry's highest capacity and lowest price-per-megabyte rack mounted, removable media disk. With 205 megabytes of user formatted capacity, 615 megabytes are available in a 42-inch high cabinet - 50% more than any other removable media product. The RA60 provides 205 megabytes of removable media flexibility for $15,000.
Some DEC marketing material refers to the RA60 as a 'Winchester' drive; strictly speaking, this is not completely accurate. It does use some aspects of Winchester drives, such as the use of pre-recorded servo information, but it does not have a sealed HDA, which many regard as the key innovation in Winchester drives.
4.3 BSD disktab
ra60|RA60|DEC RA60 Removable:\ :ty=removable:ns#42:nt#4:nc#2382:\ :pa#15884:ba#8192:fa#1024:\ :pb#33440:pc#400176:\ :pg#82080:bg#4096:fg#512:\ :ph#268772:bh#4096:fh#1024:
Further reading
- RA60 Disk Drive User Guide (EK-0RA60-UG-001 - not available online)
- RA60 Disk Drive Service Manual (EK-0RA60-SV-002 - not available online)
External links
- ra60 - documentation at Bitsavers
- RA60 Disk Drive Service Manual (EK-0RA60-SV-001l
- RA60 205-Mbyte Removable-Media Disk Drive - brochure
- The RA60, RA80 and RA81 Disk Drives and The Digital Storage Architecture - another brochure
- RA Family Of Winchester Disk Drives - and one more
- RA60 Maintenance Guide (AA-M88OB-TC)
- DEC RA60 disk drives
