The H-8589-11 disk drive was developed as a successor unit with twice the capacity of the previous generation in order to meet the increasing need for higher capacity.
The basic system of this unit was the same as that of the H-8589-1, but track pitch was halved by improving the design precision of each part. This doubled the surface recording density compared to the previous unit, and enabled a capacity of 200Mbyte per replaceable disk pack. Also, seek time was improved by 17% from the previous 30ms to 25ms by improving the seek system.
Each DKU has two spindles, and four DKUs were linked and connected to a single disk controller to create a subsystem capacity of 1,600Mbyte per house.
This unit had media compatibility with the IBM3330-1 disk unit, and disk packs could be exchanged between the two.
| Completion date | June 1975 |
|---|---|
| Memory capacity per unit | 400Mbyte/DKU |
| Memory capacity per spindle | 200Mbyte |
| BPI | 4,400BPI |
| TPI | 380TPI |
| Surface recording density | 1.8Mbit/square inch |
| Disk size/quantity | 14-inch/10 disks |
| Head type/number per actuator | Heavyweight inductive/19+1(servo) |
| Average access time | 25ms |
| Disk rotation speed | 3,600rpm |
| Data transfer speed | 806Kbyte/s |
