CPU/Memory Interconnect - Revision history

Jnc: Original name was 'Comet Memory Interconnect'

2024-05-18T18:36:15Z

Original name was 'Comet Memory Interconnect'

2024-05-15T14:25:56Z

Rename cat to be consistent with other VAX buses

2024-05-15T14:20:56Z

Add new cat

2024-05-07T23:41:35Z

More accurate new category

2022-06-03T20:01:53Z

iDs‎CMI units: add board IDs

2022-06-03T13:56:03Z

typo

2022-06-03T13:55:31Z

+ block diagram; KC750 and FP750 are not CMI options

2022-06-02T06:34:29Z

CMI configuration rules, FP750, and KC750 added

2022-06-02T01:48:04Z

Tri-state at the analog level

2022-06-01T20:07:43Z

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 [[Image:VAX750block.jpg|right|thumb|300px|VAX-11/750 system block diagram, showing how the CMI ties together the major /750 functional units]]
-The '''CPU/Memory Interconnect''' (often given as '''CMI''') is the main [[bus]] which connects the main sub-systems (such as the [[Central Processing Unit|CPU]] and [[main memory]], as well as [[input/output|I/O]] adapters) in the [[VAX-11/750]] processor. A sub-system connected to the CMI is referred to as a 'nexus'.
+The '''CPU/Memory Interconnect''' (often given as '''CMI'''; the original name was '''Comet Memory Interconnect''' - 'Comet' was the code-name of the /750)) is the main [[bus]] which connects the main sub-systems (such as the [[Central Processing Unit|CPU]] and [[main memory]], as well as [[input/output|I/O]] adapters) in the [[VAX-11/750]]. A sub-system connected to the CMI is referred to as a 'nexus'.
 The primary functions of the CMI are to do priority arbitration for use of the bus, and carry data between the sub-systems, as well as carrying [[interrupt]]s. It is also used for a variety of lesser functions, such as [[diagnostic]]s, loading writeable [[microcode]], etc.

← Older revision		Revision as of 14:25, 15 May 2024
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	[[Category: VAX Buses]]		[[Category: VAX Buses]]
−	[[Category: ~~CPU/Memory Interconnect~~]]	+	[[Category: CMI]]

← Older revision		Revision as of 14:20, 15 May 2024
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	[[Category: VAX Buses]]		[[Category: VAX Buses]]
		+	[[Category: CPU/Memory Interconnect]]

← Older revision		Revision as of 23:41, 7 May 2024
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	* [http://www.bitsavers.org/pdf/dec/vax/handbook/VAX_Hardware_Handbook_Volume_1_1986.pdf VAX Hardware Handbook Volume 1] - the CMI is covered in Chapter 9 (pp. 316-321 of the PDF)		* [http://www.bitsavers.org/pdf/dec/vax/handbook/VAX_Hardware_Handbook_Volume_1_1986.pdf VAX Hardware Handbook Volume 1] - the CMI is covered in Chapter 9 (pp. 316-321 of the PDF)

−	[[Category: ~~DEC~~ Buses]]	+	[[Category: VAX Buses]]
−	~~[[Category: VAXen~~]]

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 The CMI units present in every /750 are:
-* [[KA750 CPU]]
+* [[KA750 CPU]] - L0002-L0003-L0004-L0005/L0008
-* [[MS750 Memory System]]
+* [[MS750 Memory System]] - L0011/L0016/L0022
 Optional units include:
-* [[RH750 Massbus Adapter]]
+* [[RH750 Massbus Adapter]] - L0007
-* [[DW750 Second Unibus Interface]]
+* [[DW750 Second Unibus Interface]] - L0010
-* [[CI750 Computer Interconnect Interface]]
+* [[CI750 Computer Interconnect Interface]] - L0009
-* [[DR750 Parallel Interface]]
+* [[DR750 Parallel Interface]] - L0014
 == CMI Option Slot Configuration Rules ==

← Older revision		Revision as of 13:56, 3 June 2022
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−	[[Image:VAX750block.jpg\|right\|thumb\|300px\|VAX-11/750 system block diagram, showing ~~hoe~~ the CMI ties together the major /750 functional units]]	+	[[Image:VAX750block.jpg\|right\|thumb\|300px\|VAX-11/750 system block diagram, showing how the CMI ties together the major /750 functional units]]

	The '''CPU/Memory Interconnect''' (often given as '''CMI''') is the main [[bus]] which connects the main sub-systems (such as the [[Central Processing Unit\|CPU]] and [[main memory]], as well as [[input/output\|I/O]] adapters) in the [[VAX-11/750]] processor. A sub-system connected to the CMI is referred to as a 'nexus'.		The '''CPU/Memory Interconnect''' (often given as '''CMI''') is the main [[bus]] which connects the main sub-systems (such as the [[Central Processing Unit\|CPU]] and [[main memory]], as well as [[input/output\|I/O]] adapters) in the [[VAX-11/750]] processor. A sub-system connected to the CMI is referred to as a 'nexus'.

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 The primary functions of the CMI are to do priority arbitration for use of the bus, and carry data between the sub-systems, as well as carrying [[interrupt]]s. It is also used for a variety of lesser functions, such as [[diagnostic]]s, loading writeable [[microcode]], etc.
-The CMI is carried over a [[backplane]], into which the various sub-systems plug; it is [[synchronous]] and interlocked (like the [[Synchronous Backplane Interconnect|SBI]] of the [[VAX-11/780]]).
+The CMI is carried over a [[backplane]], into which the various sub-systems plug. It is [[synchronous]] and interlocked (like the [[Synchronous Backplane Interconnect|SBI]] of the [[VAX-11/780]]); at the [[analog]] level, it is [[tri-state]].
 ==Details==

← Older revision	Revision as of 20:07, 1 June 2022
(No difference)