Hardware Detail

Item Reference:	HW0318
Machine Type:	0681	Serial Number:
	Redwing hard disk
	Developed at Hursley, the 0681 hard disk was announced by IBM in 1990. Redwing was the Hursley Laboratory's last hard disk product. The 0681-500 had a capacity of 471MB (megabytes) on 8 platters, while the 0681-1000 had a capacity of 857MB on 12 platters. Both featured an areal density of 45.20 Mbits / sq.inch (1677 tpi * 26951 bpi). Redwing was based on 5.1/4 inch platters, the last IBM disk to use that size. Hursley's Piccolo used 8 inch platters. The read / write heads are moved by a linear actuator, possibly the last disk to use this mechanism. Redwing was the first hard disk to use PRML Technology (Digital Read Channel with 'Partial Response Maximum Likelihood' algorithm). Redwing was manufactured at the IBM plant in Havant, Hampshire.
Date of Origin:		Donor:	Malcolm Muggeridge
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Location:	On Display - HLG03	Commissioned By: Museum	Until: