RA60 Disk Drive

From Computer History Wiki
Revision as of 16:30, 18 August 2023 by Jnc (talk | contribs) (+month)
Jump to: navigation, search


RA60
Manufacturer: Digital Equipment Corporation
Year Introduced: June, 1982
Drive Controller(s): all SDI controllers
Capacity: 205 Mbytes (formatted)
Transfer Rate: 1.3 Mbytes/sec
Average Access Time: 50 msec
Revolutions per Minute: 3600 1/min
One Track Seek Time: 6.7 msec
Average Seek Time: 41.7 msec


An open RA60

The RA60 Disk Drive is a DEC SDI removable-pack disk drive, introduced in 1982. It is the only removable-pack drive in the RAxx group of drives; the others (RA70, etc) are all non-removable-media disk drives.

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.

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