RM80 Disk Drive: Difference between revisions
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[[ | {{Infobox Disk drive | ||
| name = RM80 | |||
| manufacturer = [[Digital Equipment Corporation|DEC]] | |||
| year introduced = October, 1980 | |||
| controller = [[RH11 MASSBUS controller|RH11]], [[RH70 MASSBUS controller|RH70]], [[RH10 MASSBUS controller|RH10]], [[RH20 MASSBUS controller|RH20]], [[RH780 Massbus Adapter|RH780]], [[RH750 Massbus Adapter|RH750]] | |||
| capacity = 124 Mbytes | |||
| transfer rate = 1.2 Mbytes/sec | |||
| average access time = 33.3 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 (18-bit word mode)<br>559 (16-bit word mode) | |||
| sectors = 30 (18-bit word mode)<br>31 (useable; 16-bit word mode) | |||
| words per sector = 256 (16-bit word mode) | |||
| tracks per inch = 478 | |||
| density = 6339 (max; inner track) | |||
| recording method = [[Modified Frequency Modulation|MFM]] | |||
| start time = 20 secs (avg);<br>40 secs (max) | |||
| stop time = 9 secs (avg);<br>13 secs (max) | |||
| physical size = 26cm x 44cm x 67cm | |||
| weight = 135 lbs (approx) | |||
| power consumption = 575 watts | |||
}} | |||
[[Category: | [[Image:rm80.jpg|thumb|200px|left|RM80]] | ||
The '''RM80 Disk Drive''' was a [[MASSBUS]] [[non-removable-media disk]] from [[Digital Equipment Corporation|DEC]]; it held 124 MB. It was apparently the MASSBUS version of the [[R80 Disk Drive]]; it could support either 16- or 18-bit words. It was internally operated by a [[microprocessor]] which used 32-bit burst [[error-correcting code|ECC]] to invisibly repair simple data errors. | |||
It had two heads per surface; not rotationally opposed (to halve maximum access time), but two on each arm; there were thus 1,122 usable tracks on each data surface (in 18-bit word mode; 4 tracks were reserved for maintenance purposes in 16-bit mode). 1 sector per track was reserved for bad block replacement in 16-bit word mode, out of 32 total. | |||
The RM80 can also be connected in a dual-[[hardware port|port]] arrangement, permitting its use by two [[device controller|controllers]]. | |||
==Further reading== | |||
* ''RM80 Disk Drive Technical Description Manual'' (EP-0RM80-TD-001) - not available online, but in microfiche | |||
* ''RM80 Disk Drive Service Manual'' (EP-0RM80-SV-001) - not available online, but in microfiche | |||
==External links== | |||
* [https://manx-docs.org/collections/antonio/arc-db/RM80_Disk_Drive_Service_Manual_Preliminary.pdf RM80 Disk Drive Service Manual] | |||
* [http://www.bitsavers.org/pdf/dec/disc/rm05/EK-RMADA-TD-001_Oct80.pdf RM MASSBUS Adapter Technical Description Manual] (EK-RMADA-TD-001) | |||
[[Category: MASSBUS Disk Drives]] | |||
[[Category: DEC Non-removable-media Disks]] | |||
Latest revision as of 14:23, 18 August 2023
| RM80 | |
| Manufacturer: | DEC |
|---|---|
| Year Introduced: | October, 1980 |
| Drive Controller(s): | RH11, RH70, RH10, RH20, RH780, RH750 |
| Capacity: | 124 Mbytes |
| Transfer Rate: | 1.2 Mbytes/sec |
| Average Access Time: | 33.3 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 (18-bit word mode) 559 (16-bit word mode) |
| Sectors per Track: | 30 (18-bit word mode) 31 (useable; 16-bit word mode) |
| Words per Sector: | 256 (16-bit word mode) |
| Tracks per Inch: | 478 |
| Density: | 6339 (max; inner track) |
| Recording Method: | MFM |
| Start Time: | 20 secs (avg); 40 secs (max) |
| Stop Time: | 9 secs (avg); 13 secs (max) |
| Physical Size: | 26cm x 44cm x 67cm |
| Weight: | 135 lbs (approx) |
| Power Consumption: | 575 watts |
The RM80 Disk Drive was a MASSBUS non-removable-media disk from DEC; it held 124 MB. It was apparently the MASSBUS version of the R80 Disk Drive; it could support either 16- or 18-bit words. It was internally operated by a microprocessor which used 32-bit burst ECC to invisibly repair simple data errors.
It had two heads per surface; not rotationally opposed (to halve maximum access time), but two on each arm; there were thus 1,122 usable tracks on each data surface (in 18-bit word mode; 4 tracks were reserved for maintenance purposes in 16-bit mode). 1 sector per track was reserved for bad block replacement in 16-bit word mode, out of 32 total.
The RM80 can also be connected in a dual-port arrangement, permitting its use by two controllers.
Further reading
- RM80 Disk Drive Technical Description Manual (EP-0RM80-TD-001) - not available online, but in microfiche
- RM80 Disk Drive Service Manual (EP-0RM80-SV-001) - not available online, but in microfiche
