This was a 5.25-inch magnetic disk unit Toshiba started shipping in October 1983. The MK-50FB Series had 3 models with different capacities, depending on the number of disks.
This series was developed to meet the increasing need for 5.25-inch disks as magnetic disk units for desktop PCs, and Toshiba achieved high-speed access by using VCM for head drive prior to other companies. Toshiba started OEM supply of disk units with the MK-50FB series. It was used by leading PC manufacturers, and its high-speed access capability contributed to improving the performance of PCs.
Following the MK-50FB Series, Toshiba developed other 5.25-inch magnetic disk units, including the MK-150F Series which increased storage capacity by improving bit density, and the MK-350F Series which increased storage capacity by improving bit density and track density, and increasing the number of disks.
| MK-50FB Series | MK-150F Series | MK-350F Series | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| MK- 53FB |
MK- 54FB |
MK- 56FB |
MK- 153F |
MK- 154F |
MK- 156F |
MK- 355F |
MK- 356F |
MK- 358F |
||
| Capacity (MB) |
Un formatted |
43.2 | 60.5 | 86.5 | 86.5 | 121.0 | 173.0 | 467.1 | 570.9 | 778.5 |
| Formatted | 34.0 | 47.6 | 68.0 | 73.9 | 103.5 | 147.8 | 405.7 | 495.8 | 676.1 | |
| Data transfer rate (Mbps) | 5 | 10 | 15 | |||||||
| Bit density(bit/inch) | 9,383 | 18,766 | 31,248 | |||||||
| Track density(track/inch) | 900 | 900 | 1,450 | |||||||
| Recording system | MFM | 2-7 RLL CODE | 2-7 RLL CODE | |||||||
| Rotation speed(rpm) | 3,600 | 3,600 | 3,600 | |||||||
| Average access time (msec) | 24 | 23 | 16 | |||||||
| Number of cylinders | 830 | 830 | 1,660 | |||||||
| Number of disks | 3 | 4 | 6 | 3 | 4 | 6 | 5 | 6 | 8 | |
| Number of data heads | 5 | 7 | 10 | 5 | 7 | 10 | 9 | 11 | 15 | |
| External dimensions(W, D, H) mm | 146.1×203.2×82.5 | 146.1×203.2×82.5 | 146.1×203.2×82.5 | |||||||
| Weight (kg) | 3.0 | 3.0 | 3.0 | |||||||
