【Mitsubishi Electric】 E1880 Series Magnetic Disk Units

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.
Main Specifications of E1880D Magnetic Disk Unit
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)
(Without built-in device controller)

E1880D Magnetic Disk Unit