IBM System/360 Model 195
{{Short description|High-end IBM computer model from 1970s}}
{{Infobox computing device
| name = IBM System/360 Model 195
| logo = IBM Logo 1967-1972.svg
| logo_size = 120px
| image = Bundesarchiv B 145 Bild-F038812-0017, Wolfsburg, VW Autowerk, EDV.jpg
| image_size = 270px
| caption =
| developer = IBM
| release date = August 20, 1969
| price = $7–12.5 million
| discontinued = February 9, 1977
| predecessor = IBM S/360 Model 91
| successor = IBM S/370 Model 195
}}
The IBM System/360 Model 195 is a discontinued IBM computer introduced on August 20, 1969. The Model 195 was a reimplementation of the IBM System/360 Model 91 design using monolithic integrated circuits.{{cite mailing list|url=https://groups.yahoo.com/neo/groups/hercules-390/conversations/messages/53873|title=The 360/91 and associated machines|author=gah|date=April 20, 2008|mailing-list=hercules-390@yahoogroups.com}} It offers "an internal processing speed about twice as fast as the Model 85, the next most powerful System/360".{{cite web|url=https://www.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP2195.html|title=IBM Archive: System/360 Model 195|website=IBM|date=23 January 2003|access-date=June 28, 2017|archive-url=https://web.archive.org/web/20230729090329/https://www.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP2195.html|archive-date=2023-07-29|url-status=dead}} The Model 195 was discontinued on February 9, 1977, the same date as the System/370 Model 195.
About 20 Model 195 systems were produced.{{cite web|url=https://people.computing.clemson.edu/~mark/eager.html|title=Eager Execution / Dual Path / Multiple Path|author=Mark Smotherman|quote=15 Model 91's and 2 Model 95's were built. Approximately twenty Model 195's were built.}}{{cite web |url=https://pdfs.semanticscholar.org/ceea/f56b486b7290c8638d3781e53de3229efda7.pdf|archive-url=https://web.archive.org/web/20161221084029/https://pdfs.semanticscholar.org/ceea/f56b486b7290c8638d3781e53de3229efda7.pdf|archive-date=December 21, 2016|url-status=dead|title=Some Reflections on Computer Engineering: 30 Years after the IBM System 360 Model 91 |website=Semantic Scholar |author=Michael J. Flynn|author-link=Michael J. Flynn|date=December 2, 1997|s2cid=5958256|quote=About twenty Model 91s were made, and perhaps an equivalent number of the Model 195.}}
Technical specifications
The basic CPU cycle time is 54 nanoseconds (ns). The system has a high degree of parallelism and can process up to seven operations at a time.
The system can be configured with 1, 2, or 4 MB of magnetic core memory (models 195J, 195K, and 195L) with a cycle time of 756 ns. A 32 KB cache, called a buffer memory in the IBM announcement, is standard. Memory blocks are brought into cache in units of 64 bytes.
The normal operating system for the Model 195 is OS/360 Multiprogramming with a Variable Number of Tasks (MVT).
Components
The 360/195 has the following components:{{cite book
| title = IBM System/360 Model 195 - Functional Characteristics
| id = A22-6943-O
| date = August 1969
| edition = First
| section = System Components
| section-url = http://bitsavers.org/pdf/ibm/360/functional_characteristics/GA22-6943-1_360-195_Functional_Characteristics_197008.pdf#page=6
| pages = 6-8
| url = http://bitsavers.org/pdf/ibm/360/functional_characteristics/GA22-6943-1_360-195_Functional_Characteristics_197008.pdf
| series = Systems Reference Library
| access-date = April 16, 2025
}}
- 2160 Model l System Console
- 2180 CPU Power Unit{{efn|Model depends on configuration.}}
- 2185 Power Distribution Unit
- 2186 Coolant Distribution Unit
- 2195 Processing Unit (which includes the Processor Storage)
- 2860 Selector Channel{{efn|Optional, but there must be at least one channel.|name=chan}}
- 2870 Multiplexer Channel{{efn|name=chan}}
- 2880 Block Multiplexer Channel{{efn|name=chan}}
Legacy
The Model 195 was later updated as the IBM System/370 Model 195 with the new System/370 instructions and the 370 time-of-day clock and control registers, but without the virtual memory hardware.{{cite web|url=http://www.beagle-ears.com/lars/engineer/comphist/model360.htm|title=IBM 360/370/3090/390 Model Numbers}}
Notes
{{Notelist}}
References
{{Reflist}}
External links
- [http://bitsavers.org/pdf/ibm/360/functional_characteristics/GA22-6943-1_360-195_Functional_Characteristics_197008.pdf IBM System/360 Model 195 Functional Characteristics]
{{IBM System/360 line}}
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