Difference between revisions of "RM80 Disk Drive"

From Computer History Wiki
Jump to: navigation, search
m (External links: +RM80 Service Manual)
(Add infobox, some text)
 
(5 intermediate revisions by the same user not shown)
Line 1: Line 1:
[[Image:rm80.jpg|thumb|200px|right|RM80]]
+
{{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
 +
}}
  
121 MB with [[MASSBUS]] interface, 1200 KB/s, 33.3 ms average access, 25 ms average seek, 6 ms track-to-track seek time, 3600 rpm
+
[[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==
 
==External links==
Line 8: Line 45:
 
* [http://www.bitsavers.org/pdf/dec/disc/rm05/EK-RMADA-TD-001_Oct80.pdf RM MASSBUS Adapter Technical Description Manual] (EK-RMADA-TD-001)
 
* [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 Devices]]
+
[[Category: MASSBUS Disk Drives]]
[[Category: DEC Disk Drives]]
+
[[Category: DEC Non-removable-media Disks]]

Latest revision as of 15:23, 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


RM80

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

External links