RA70 disk drive: Difference between revisions
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[[ | {{Infobox Disk drive | ||
| name = RA70 | |||
| manufacturer = [[Digital Equipment Corporation|DEC]] | |||
<!-- | year introduced = 198x --> | |||
| controller = [[Standard Disk Interconnect#SDI Family of DSA Products|all SDI controllers]] | |||
| capacity = 280 Mbytes (formatted)<br>350 Mbytes (unformatted) | |||
| transfer rate = 1.4 Mbytes/sec | |||
| average access time = 27 msec | |||
| rpm = 4000 | |||
| revolution time = 7.5 msec | |||
<!-- | one track seek = x msec --> | |||
| average seek = 19.5 msec | |||
<!-- | maximum seek = x msec --> | |||
| surfaces = 11 data, 1 servo | |||
| number of heads = 11 data,<br>1 servo | |||
| tracks = 1507 | |||
| sectors = 34 | |||
| bytes per sector = 512 | |||
| tracks per inch = 1355 | |||
| density = 22,437 | |||
<!-- | recording method = [[Modified Frequency Modulation|MFM]] --> | |||
| start time = 59 secs (avg) | |||
| stop time = 15 secs (avg) | |||
| physical size = 9cm x 14.6cm x 22.4cm | |||
| weight = 10.5 lbs | |||
| power consumption = 264 watts (idle) | |||
}} | |||
[[Category:MSCP Disk Drives]] | [[Image:ra70.jpg|thumb|left|200px|RA70]] | ||
The '''RA70 disk drive''' is a [[Standard Disk Interconnect]] [[non-removable-media disk]] drive from [[Digital Equipment Corporation|DEC]]. Unlike all the other RA-series drives, it is a compact width - 5.25 inches wide. It has no internal [[power supply]]; it gets its power from the host system, or its SA7x enclosure. | |||
Its capacity was 280 Mbytes (formatted). It was internally operated by a [[microprocessor]] which used 32-bit burst [[error-correcting code|ECC]] to invisibly repair simple data errors. | |||
{{stub}} | |||
==Further reading== | |||
* ''RA70 Disk Drive Technical Description Manual'' (EK–ORA70–TD) - not available online | |||
* ''RA7x Disk Drive Service Manual'' (EK–ORA7X-SM) - not available online | |||
==External links== | |||
* [http://bitsavers.org/pdf/dec/brochures/DEC-RA-FamilyOfWinchesterDiskDrives.pdf RA Family Of Winchester Disk Drives] - brochure | |||
<!-- * [http://bitsavers.org/pdf/dec/disc/ra70/ ra70] - documentation at [[Bitsavers]] --> | |||
* [https://manx-docs.org/collections/mds-199909/cd3/disk/rsa7xpg2.pdf RA7x/SA7x Pocket Reference Guide] (EK–RSA7X–PG–002) | |||
[[Category: MSCP Disk Drives]] | |||
[[Category: DEC Non-removable-media Disks]] | |||
Revision as of 20:45, 16 August 2023
| RA70 | |
| Manufacturer: | DEC |
|---|---|
| Drive Controller(s): | all SDI controllers |
| Capacity: | 280 Mbytes (formatted) 350 Mbytes (unformatted) |
| Transfer Rate: | 1.4 Mbytes/sec |
| Average Access Time: | 27 msec |
| Revolutions per Minute: | 4000 |
| 1/2 Revolution Time: | 7.5 msec |
| Average Seek Time: | 19.5 msec |
| Total Surfaces: | 11 data, 1 servo |
| Number of Heads: | 11 data, 1 servo |
| Tracks per Surface: | 1507 |
| Sectors per Track: | 34 |
| Bytes per Sector: | 512 |
| Tracks per Inch: | 1355 |
| Density: | 22,437 |
| Start Time: | 59 secs (avg) |
| Stop Time: | 15 secs (avg) |
| Physical Size: | 9cm x 14.6cm x 22.4cm |
| Weight: | 10.5 lbs |
| Power Consumption: | 264 watts (idle) |
The RA70 disk drive is a Standard Disk Interconnect non-removable-media disk drive from DEC. Unlike all the other RA-series drives, it is a compact width - 5.25 inches wide. It has no internal power supply; it gets its power from the host system, or its SA7x enclosure.
Its capacity was 280 Mbytes (formatted). It was internally operated by a microprocessor which used 32-bit burst ECC to invisibly repair simple data errors.
Further reading
- RA70 Disk Drive Technical Description Manual (EK–ORA70–TD) - not available online
- RA7x Disk Drive Service Manual (EK–ORA7X-SM) - not available online
External links
- RA Family Of Winchester Disk Drives - brochure
- RA7x/SA7x Pocket Reference Guide (EK–RSA7X–PG–002)
