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IBM System/370 Model 165

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This is an old revision of this page, as edited by Guy Harris (talk | contribs) at 03:45, 27 December 2016 (→Growth path: Redo the bit about the S/360 Model 85 the same way it's done in the page for the Model 85 - more in-line stuff, fewer footnotes.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
ManufacturerInternational Business Machines Corporation (IBM)
Product familySystem/370
Release dateJune 30, 1970 (1970-06-30)
DiscontinuedDecember 23, 1977
WebsiteOfficial website IBM Archives
3 months after the announcement of
the 370/165 (and 155)
came the Model 145.[1]
Unlike the 165 (or 155),
the 145's lack of virtual memory could be rectified with a simple microcode update from a floppy disk, vs the others needing a hardware upgrade.

The IBM System/370 Model 165 (and the Model 155[2]) were jointly announced June 30, 1970[3] as "designed for ... the Seventies." That same day IBM announced the 370/195[4]

Three months later a fourth IBM System/370, the Model 145, was announced. Since none of them came with virtual memory, "which was to be a hallmark of the 370 line"[5] some said about these early members, of the IBM System/370 family, especially about the 165 & 155, that they were not "the real 370 line."[NB 1]

Growth path

The initially announced System/370 Models 165 & 155 systems were in many ways merely improved IBM System/360 systems.

Upgrade option

In 1972 an upgrade option for the 370/165 (and 155) was announced "to provide the hardware necessary to operate in a virtual memory mode."[8] After being upgraded, these systems were referred to as 165-II and 155-II. [9]

Even before upgrading

Even when they lacked a DAT box, merely operating as an "extended, but not redesigned" system, these machines introduced some new instructions, such as MOVE CHARACTER LONG (MVCL) and COMPARE CHARACTER LONG (CLCL), thereby permitting operations on up to 2^24-1 bytes (16 MB), vs. the 256-byte limits on the 360's MVC and CLC.[10][11], but lacked a DAT box.

Emulation

The IBM 7070/7074 Compatibility Feature allowed the 165 to "run 7070 and 7074 programs at speeds that, in general, equal or exceed those of the original systems"[12]and yet "not affect normal operation of System/370."[12]: p.5 

See also

Notes

  1. ^ The 195 was noted as "at the time of its introduction, ... IBM's most powerful computing system" and the 145's microcode could be upgraded from a floppy disk. By contrast, the 155 & 165 needed a hardware addition priced at $200,000 and $400,000 respectively
  2. ^ The Model 155 was also enabled to "run under DOS support."

References

  1. ^ "System/370 Model 145". IBM Archives. IBM.
  2. ^ "System/370 Model 155". IBM Archives. IBM.
  3. ^ a b "System/370 Model 165". IBM Archives. IBM.
  4. ^ coming about 14 months after the announcement of the 360/195. Both 195 machines were withdrawn Feb. 9, 1977. see https://www-03.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP2195.html and https://www-03.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP3195.html
  5. ^ "What Course for the 3081?". Computerworld. November 24, 1980. p. 34.
  6. ^ Robert L. Asenhurst. Foundations of Microprogramming. p. 34. ISBN 1483215873.
  7. ^ Jon Elson (December 5, 2014). "IBM 360/85 vs. 370/165". Newsgroup: alt.folklore.computers.
  8. ^ "First IBM DAT Box Installed". Computerworld. August 15, 1973. p. 17.
  9. ^ A. Padegs (September 1981). "System/360 and Beyond". IBM Journal of Research & Development. IBM. 25 (5): 377–390. doi:10.1147/rd.255.0377. – tables include model characteristics (Table 1) and announcement/shipment dates (Table 2). The S/370-155-II and -165-II are listed under the former but not the latter, because the upgraded systems were not formally announced as separate models. The "System/370 Advanced Function" announcement, including the -158 and -168, was the main public event.
  10. ^ http://faculty.cs.niu.edu/~byrnes/csci360/notes/360ex.htm
  11. ^ http://research.microsoft.com/en-us/um/people/gbell/tcmwebpage/timeline/chap51_ibm370_cs2.pdf
  12. ^ a b "7070/7074 Compatibility Feature for IBM System/370 Models 165, 165 II, and 168" (PDF). IBM. June 1973.
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