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IBM System/370 Model 145

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This is an old revision of this page, as edited by Guy Harris (talk | contribs) at 06:56, 12 May 2024 (Everything in "New capabilities" applies to all of the initial S/370 machines, not just the Model 145, and is now in IBM System/370#Initial models and does not belong here.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
IBM System/370 Model 145
IBM System/370 Model 145
ManufacturerInternational Business Machines Corporation (IBM)
Product familySystem/370
GenerationThird
Release dateSeptember 23, 1970 (1970-09-23)
Introductory price$705,775 to $1,783,000
Memorysemiconductor (first IBM use for main memory), 112–512 KB
StorageIBM 3330, IBM 2319
Backward
compatibility		IBM System/360, IBM 1400 series, IBM 7010
WebsiteOfficial website IBM Archives
Render of S/370 Model 145 with typical peripherals
IBM System/370 Model 145 system console
IBM monolithic memory card

The IBM System/370 Model 145 was announced September 23, 1970,[1] three months after the 155 and 165[2] models. It was the fourth member of the IBM System/370 line of computers,[a] and was the first IBM computer to use semiconductor memory for its main memory instead of magnetic core memory.[4] It was described as being five times faster than the IBM System/360 Model 40. First shipments were scheduled for late summer of 1971.[1]

Virtual memory

Some said about the early members of the IBM System/370 family, looking back, that they were not "the real 370 line" because "neither offered virtual storage capability, which was to be a hallmark of the 370 line."[5]

Unlike the earlier Model 155 and 165 systems, for which an upgrade to virtual memory required the purchase of an expensive upgrade to add a DAT box,[5] the 145's customers had two advantages:

  • 370/145 customers did not have to wait as long for this lack of virtual memory to be remedied[b]
  • there was no need to buy extra hardware: An upgrade to the 145's microcode through a new microcode floppy disk[6] enabled virtual memory capability.

VM/CMS

Upon gaining virtual memory capability via a microcode update, the 145 could now support the VMF (Virtual Machine Facility) and VM/CMS, a time-sharing system.

See also

Notes

  1. ^ A third 370, the 370/195, had separately been announced the same day as the 155 & 165.[3]
  2. ^ June 1971 vs. Aug. 1972

References

  1. ^ a b "System/370 Model 145". IBM Archives. IBM. 23 January 2003. Archived from the original on 2023-07-29.
  2. ^ "System/370 Model 165". IBM Archives. IBM. 23 January 2003. Archived from the original on 2023-07-29.
  3. ^ "System/370 Model 195". IBM Archives. IBM. 23 January 2003. Archived from the original on 2023-07-29.
  4. ^ William D. Smith (September 24, 1970). "A new computer unveiled by I.B.M". The New York Times.
  5. ^ a b "What Course for the 3081?". Computerworld. November 24, 1980. p. 34.
  6. ^ IBM Maintenance Library 3145 Processing Unit Theory - Maintenance. IBM. pp. CPU 117–129. SY24-3581-2
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