This was a series of high-capacity, high-performance, space-saving, energy-saving magnetic disk units for the EX830II, EX840II and EX850II general-purpose computer systems announced by Mitsubishi Electric in 1988. Memory capacity per unit ranged from a minimum of 0.63Gbyte (E1880B) to a maximum of 5GB (E1880D), and capacity could be selected or expanded in 0.63GB units.
These units had the following features:
- Data processing capacity was improved by reducing head positioning time from the previous 16ms to 13ms, and achieving a data transfer speed of 3Mbyte/s.
- Expansion was easy. Expansion could be done in 0.63Gbyte units, and expansion of device cross call functions could be done at the customer's installation location.
- Greater compactness was achieved by using 8.8-inch magnetic disks, and adopting a modular structure with 0.63Gbyte units. Twice the capacity (5Gbyte) could be installed in half the floor space of the previous machine (0.7m2).
- High-density recording at 21,500bit/inch and 1,060track/inch was achieved by combining a thin-film head with a high-performance coated disk, and improving recording/playback circuit technology.
| Equipment configuration | Number of spindles/unit | 8 |
|---|---|---|
| Actuators/spindle | 1 | |
| Media configuration | Cylinders/actuator | 885 + alternate 1 |
| Tracks/cylinder | 15 | |
| Memory capacity | Unit | 5,040Mbyte |
| Actuator | 630Mbyte | |
| Cylinder | 712,140byte | |
| Track | 47,476byte | |
| Recording system | 2-7 RLLC | |
| Bit density | 21,500bit/inch | |
| Track density | 1,060track/inch | |
| Performance | Positioning time | Average 13ms |
| otational delay | Average 8.29ms | |
| Data transfer speed | 3Mbyte/s | |
| External dimensions(Width×Depth×Height) | 975mm×780mm×1,400mm (With built-in device controller) 700mm×780mm×1,400mm (Without built-in device controller) |
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