RA80 Disk Drive: Difference between revisions
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[[ | {{Infobox Disk drive | ||
| name = RA80 | |||
| manufacturer = [[Digital Equipment Corporation|DEC]] | |||
<!-- | year introduced = 198x --> | |||
| controller = [[Standard Disk Interconnect#SDI Family of DSA Products|all SDI controllers]] | |||
| capacity = 121 Mbytes | |||
| transfer rate = 1.2 Mbytes/sec | |||
| average access time = 33 msec | |||
| rpm = 3600 | |||
| revolution time = 8.3 msec | |||
| one track seek = 6 msec | |||
| average seek = 25 msec | |||
| maximum seek = 50 msec | |||
| surfaces = 7 data, 1 servo | |||
| number of heads = 14 data,<br>1 servo (read-only) | |||
| tracks = 561 per head (total)<br>546 (usable for data) | |||
| sectors = 31 | |||
| bytes per sector = 512 | |||
| tracks per inch = 478 | |||
| density = 6339 (max; inner track) | |||
| recording method = [[Modified Frequency Modulation|MFM]] | |||
| start time = 15 secs (avg);<br>40 secs (max) | |||
<!-- | stop time = 9 secs (avg);<br>13 secs (max) --> | |||
| physical size = 26cm x 44cm x 67cm | |||
| weight = 147 lbs (approx) | |||
| power consumption = 720 watts | |||
}} | |||
[[Image:ra80.jpg|thumb|200px|left|RA80]] | |||
The '''RA80 Disk Drive''' is a [[Standard Disk Interconnect]] [[non-removable-media disk]] drive from [[Digital Equipment Corporation|DEC]]. A physically large drive (14-inch platters, in a heavy enclosure 10.5" x 16" x 36"), its capacity was 121 Mbytes. | |||
= 4.3 BSD disktab = | It had two heads per surface; not rotationally opposed (to halve maximum access time), but two on each arm; there thus 1,092 usable tracks on each surface. It was internally operated by a [[microprocessor]] which used 32-bit burst [[error-correcting code|ECC]] to invisibly repair simple data errors. | ||
It was apparently the SDI version of the [[R80 Disk Drive]]. The RA80 can also be connected in a dual-[[hardware port|port]] arrangement, permitting its use by two [[device controller|controllers]]. | |||
==4.3 BSD disktab== | |||
<pre> | <pre> | ||
a80|RA80|DEC RA80 Winchester:\ | a80|RA80|DEC RA80 Winchester:\ | ||
| Line 16: | Line 45: | ||
</pre> | </pre> | ||
[[Category: | {{semi-stub}} | ||
==External links== | |||
* [http://bitsavers.org/pdf/dec/disc/ra80/ ra80] - documentation at [[Bitsavers]] | |||
** [http://bitsavers.org/pdf/dec/disc/ra80/EK-0RA80-UG-001_UsersGuide_Jan82.pdf RA80 Disk Drive User Guide] (EK-0RA80-UG-001) | |||
* [http://bitsavers.org/pdf/dec/disc/brochure/RA60_RA80_And_RA81_Disk_Drives_Brochure_Aug82.pdf The RA60, RA80 and RA81 Disk Drives and The Digital Storage Architecture] - brochure | |||
[[Category: SDI Disk Drives]] | |||
[[Category: DEC Non-removable-media Disks]] | |||
Latest revision as of 01:16, 31 August 2023
| RA80 | |
| Manufacturer: | DEC |
|---|---|
| Drive Controller(s): | all SDI controllers |
| Capacity: | 121 Mbytes |
| Transfer Rate: | 1.2 Mbytes/sec |
| Average Access Time: | 33 msec |
| Revolutions per Minute: | 3600 |
| 1/2 Revolution Time: | 8.3 msec |
| One Track Seek Time: | 6 msec |
| Average Seek Time: | 25 msec |
| Maximum Seek Time: | 50 msec |
| Total Surfaces: | 7 data, 1 servo |
| Number of Heads: | 14 data, 1 servo (read-only) |
| Tracks per Surface: | 561 per head (total) 546 (usable for data) |
| Sectors per Track: | 31 |
| Bytes per Sector: | 512 |
| Tracks per Inch: | 478 |
| Density: | 6339 (max; inner track) |
| Recording Method: | MFM |
| Start Time: | 15 secs (avg); 40 secs (max) |
| Physical Size: | 26cm x 44cm x 67cm |
| Weight: | 147 lbs (approx) |
| Power Consumption: | 720 watts |
The RA80 Disk Drive is a Standard Disk Interconnect non-removable-media disk drive from DEC. A physically large drive (14-inch platters, in a heavy enclosure 10.5" x 16" x 36"), its capacity was 121 Mbytes.
It had two heads per surface; not rotationally opposed (to halve maximum access time), but two on each arm; there thus 1,092 usable tracks on each surface. It was internally operated by a microprocessor which used 32-bit burst ECC to invisibly repair simple data errors.
It was apparently the SDI version of the R80 Disk Drive. The RA80 can also be connected in a dual-port arrangement, permitting its use by two controllers.
4.3 BSD disktab
a80|RA80|DEC RA80 Winchester:\
:ty=winchester:ns#31:nt#14:nc#559:\
:pa#15884:ba#8192:fa#1024:\
:pb#33440:pc#242606:\
:pg#82080:bg#4096:fg#512:\
:ph#111202:bh#4096:fh#1024:
External links
- ra80 - documentation at Bitsavers
- RA80 Disk Drive User Guide (EK-0RA80-UG-001)
- The RA60, RA80 and RA81 Disk Drives and The Digital Storage Architecture - brochure
