IBM System/360 Model 75
The IBM System/360 Model 75 was a high end / high performance[1] system that was introduced April 22, 1965.[2] Although it played many roles in IBM's System 360 lineup,[3] it accounted for a small fraction of a percent of the 360 systems sold.[4]
Models
Three models[5] of the 360/75 were offered by IBM.[1]: p.5 The H75, I75 and J75 were respectively configured with one, two or four IBM 2365 Model 3 Processor Storage units, each of which provided 262,l44 bytes of core memory.[6]
Performance
The high performance of the Model 75 was attributed[1] to half a dozen advanced features, including Parallel arithmetic, Overlapped memory fetch and Parallel addition for address calculation.
Furthermore, independent storage sections provided two-way (H75) or four-way (I75, J75) interleaving of memory access. Even with only two-way interleaving, "an effective sequential access rate of 400 nanoseconds per double word (eight bytes) is possible."
External Photos
- http://ibiblio.org/comphist/node/105
- http://www-03.ibm.com/ibm/history/exhibits/mainframe/images/overlay/2423PH2075.jpg
See also
- IBM System/360 Model 20
- IBM System/360 Model 22
- IBM System/360 Model 25
- IBM System/360 Model 30
- IBM System/360 Model 40
- IBM System/360 Model 44
- IBM System/360 Model 50
- IBM System/360 Model 65
- IBM System/360 Model 67
- IBM System/360 Model 85
- IBM System/360 Model 91
References
- ^ a b c "IBM System/360 Model 75 Functional Characteristics" (PDF). IBM. A22-6889-0.
- ^ IBM Archives: System/360 Model 75
- ^ high end Main processor under ASP when the latter was introduced in 1967, high end Support Processor, and more than one Time-sharing option: TSO and CALL/OS
- ^ An ADP Newsletter cited on page 56 in Weiss, Eric A. (ed) (1969). Computer USage Essentials. McGraw-Hill. LCCN 71-76142.
{{cite book}}:|first1=has generic name (help) says (re S/360) "75-91 .. 0.1%" - ^ Lower case "M"
- ^ Thus the H75 had 262,144 bytes of core, the I75 had 524,288 and the I75 1,048,576