R80 Disk Drive
From Computer History Wiki
| R80 | |
| Manufacturer: | DEC |
|---|---|
| Capacity: | 124 Mbytes |
| Transfer Rate: | 1.2 Mbytes/sec |
| 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 |
| Sectors per Track: | 30 (18 bit words) 31 (16 bit words) |
| Words per Sector: | 256 |
| 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 R80 is a non-removable-media disk drive from DEC; its capacity was 124 Mbytes. It could support either 16- or 18-bit words, and was internally operated by a microprocessor which used 32-bit burst ECC to invisibly repair simple data errors.
It apparently had several options for how it connected to the system, and was identified differently depending on which one was used, as follows:
- an R80 connected to the system through a MASSBUS adapter (MBA) was denominated an RM80;
- an R80 connected to the system through the Standard Disk Interconnect (SDI) bus was denominated an RA80;
- an R80 connected to a VAX-11/730 through an RB730 Integrated Disk Controller was denominated an RB80. (An RB730 can have a maximum of four drives; at most one can be an RB80.)
External links
- r80 - documentation at Bitsavers
- R80 Disk Drive User's Guide (EK-00R80-UG-001)
