【NEC】 N276 Magnetic Disk Pack Unit

In October 1971, NEC announced the N276 magnetic disk pack which used a 14-inch disk pack with a memory capacity of 100MB. It was announced together with the NEAC Series 2200 Model 375 and 575, and the first shipment was in August 1973. This unit employed magnetic disk media equivalent to the IBM3336. Ease of operation and maintenance were improved by reducing seek time and rotational delay, and enabling diagnosis of an offline disk pack in parallel with online operation under the control of the N266 disk controller.

N276 Magnetic Disk Pack Unit Specifications
Total memory capacity(Mchar/pack) 97.8
Seek time(msec) 10-55,Average 30
Average rotational delay(msec) 8.4
Data transfer speed(Kchar/s) 806
Disk diameter(inch) 14
Number of disks/pack 12
Number of recording sides/pack 19
Number of cylinders/pack (figure in parentheses is for alternates) 404+(7)
Recording system MFM
Recording density(bpi) 4040
Track density(tpi) 192
Rotation speed(rpm) 3,600
Unit dimensions(mm) 600(W)×1250(D)×1000(H)

N276 Magnetic Disk Pack Unit