In August 1966, NEC announced the E261, their first magnetic disk unit, developed for small systems. It was first shipped in March 1968.
This unit was for small computer systems using magnetic disk packs comprised of five 14-inch media, and it employed the fixed data length system based on sector marks.
It was used with small computers such as the NEAC Series 2200 Model 50, and the NEAC-3100 multi-purpose scientific computer.
| Total Memory capacity(Kchar/pack) | 819 |
|---|---|
| Seek time(msec) | Average 200 |
| Average rotational delay(msec) | 14 |
| Data transfer speed (Kchar/s) | 83.3 |
| Disk diameter(inch) | 14 |
| Number of disks/pack | 5 |
| Number of recording sides/pack | 8 |
| Number of tracks/recording side | 64 |
| Number of sectors/track | 16 |
| Memory capacity of 1 sector (char) | 100 |
| Recording system | FM |
| Rotation speed(rpm) | 2100 |
