MASSBUS - Revision history

Jnc: +Category

2023-12-02T19:36:12Z

+Category

← Older revision		Revision as of 19:36, 2 December 2023
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	The first two and EXC are bi-directional; all the others are from entity to controller, except for WCLK and RUN.		The first two and EXC are bi-directional; all the others are from entity to controller, except for WCLK and RUN.

	==External ~~link~~==		==External links==

	* [http://www.bitsavers.org/pdf/dec/standards/DEC_STD_159_Massbus_Specificaton.pdf DEC STD 159] - MASSBUS Specification		* [http://www.bitsavers.org/pdf/dec/standards/DEC_STD_159_Massbus_Specificaton.pdf DEC STD 159] - MASSBUS Specification
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	[[Category: DEC Buses]]		[[Category: DEC Buses]]
	[[Category: DEC Documentation Errors]]		[[Category: DEC Documentation Errors]]
			[[Category: DEC Interface Standards]]

Jnc: /* External link */ +RM MASSBUS Adapter Technical Description Manual

2023-08-15T14:56:53Z

External link: +RM MASSBUS Adapter Technical Description Manual

← Older revision		Revision as of 14:56, 15 August 2023
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	* [http://www.bitsavers.org/pdf/dec/standards/DEC_STD_159_Massbus_Specificaton.pdf DEC STD 159] - MASSBUS Specification		* [http://www.bitsavers.org/pdf/dec/standards/DEC_STD_159_Massbus_Specificaton.pdf DEC STD 159] - MASSBUS Specification
			* [http://www.bitsavers.org/pdf/dec/disc/rm05/EK-RMADA-TD-001_Oct80.pdf RM MASSBUS Adapter Technical Description Manual] (EK-RMADA-TD-001)
	* [http://simh.trailing-edge.com/docs/massbusmystery.pdf A Massbus Mystery]		* [http://simh.trailing-edge.com/docs/massbusmystery.pdf A Massbus Mystery]

Jnc: + Category: DEC Documentation Errors

2022-10-25T13:41:11Z

+ Category: DEC Documentation Errors

← Older revision		Revision as of 13:41, 25 October 2022
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	[[Category: MASSBUS]]		[[Category: MASSBUS]]
	[[Category: DEC Buses]]		[[Category: DEC Buses]]
			[[Category: DEC Documentation Errors]]

Jnc: +goals

2022-06-05T19:51:30Z

+goals

← Older revision		Revision as of 19:51, 5 June 2022
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	The '''MASSBUS''' was a high-speed [[input/output\|I/O]] [[bus]] devised by [[Digital Equipment Corporation\|DEC]], and used to connect DEC systems to high-speed [[disk]] [[drive]]s and [[magnetic tape\|tape]] controllers such as the [[RP04 disk drive\|RP04]], [[RP06 disk drive\|RP06]], [[TM02]] and [[TM03]].		The '''MASSBUS''' was a high-speed [[input/output\|I/O]] [[bus]] devised by [[Digital Equipment Corporation\|DEC]], and used to connect DEC systems to high-speed [[disk]] [[drive]]s and [[magnetic tape\|tape]] controllers such as the [[RP04 disk drive\|RP04]], [[RP06 disk drive\|RP06]], [[TM02]] and [[TM03]].

			Two major goals of using a common I/O bus were:

			* to allow a single [[device controller]] to handle multiple different [[peripheral]]s;
			* to allow DEC's main computer families (initially the [[PDP-10]] and [[PDP-11]]; later also the [[VAX]]en) to share a common set of peripherals.

	The basic concept was suggested by [[Gordon Bell]] in July, 1972, and a committee of DEC engineers was formed to produce the first version of the specification, which came out in August.		The basic concept was suggested by [[Gordon Bell]] in July, 1972, and a committee of DEC engineers was formed to produce the first version of the specification, which came out in August.

Jnc: Fix VAX controller, avoid redir

2022-05-28T12:25:28Z

Fix VAX controller, avoid redir

← Older revision		Revision as of 12:25, 28 May 2022
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	The fact that the MASSBUS connects to disk '''drives''' and tape '''controllers''' causes terminological difficulties, since there is also a 'controller' to connect the MASSBUS to the host computer. Hence, the term 'device' will be used in this article to refer, generically, to things connected to the MASSBUS (other than the controller in the host system). A single MASSBUS can contain up to 8 devices.		The fact that the MASSBUS connects to disk '''drives''' and tape '''controllers''' causes terminological difficulties, since there is also a 'controller' to connect the MASSBUS to the host computer. Hence, the term 'device' will be used in this article to refer, generically, to things connected to the MASSBUS (other than the controller in the host system). A single MASSBUS can contain up to 8 devices.

	A variety of controllers existed to connect a MASSBUS to various kinds of DEC systems: the [[RH10 MASSBUS controller\|RH10]] for the [[PDP-10]], the [[RH20 MASSBUS controller\|RH20]] for the [[KL10]], the [[RH11 MASSBUS controller\|RH11]] for the [[UNIBUS]] (usually on a [[PDP-11]]), the [[RH70 MASSBUS controller\|RH70]] for the [[PDP-11/70]], the [[RH750 ~~MASSBUS controller~~\|RH750]] for the [[VAX-11/750~~\|VAX-11/75x~~]], and the [[RH780]] for the [[Synchronous Backplane Interconnect]] bus found on [[VAX-11/780\|VAX-11/78x]], VAX 86xx, etc.		A variety of controllers existed to connect a MASSBUS to various kinds of DEC systems: the [[RH10 MASSBUS controller\|RH10]] for the [[PDP-10]], the [[RH20 MASSBUS controller\|RH20]] for the [[KL10]], the [[RH11 MASSBUS controller\|RH11]] for the [[UNIBUS]] (usually on a [[PDP-11]]), the [[RH70 MASSBUS controller\|RH70]] for the [[PDP-11/70]], the [[RH750 Massbus Adapter‎‎\|RH750]] for the [[VAX-11/750]], and the [[RH780 Massbus Adapter‎‎\|RH780]] for the [[Synchronous Backplane Interconnect]] bus found on [[VAX-11/780\|VAX-11/78x]], VAX 86xx, etc.

	The [[PDP-15]] could also connect to MASSBUS devices via the [[UC15]] ~~Unichannel~~, but this used a [[PDP-11/05]] acting as a slave to the PDP-15 via shared memory, and also an RH11 on the -11/05's UNIBUS.		The [[PDP-15]] could also connect to MASSBUS devices via the [[UNICHANNEL 15 System\|UC15 Unichannel]], but this used a [[PDP-11/05]] acting as a slave to the PDP-15 via shared memory, and also an RH11 on the -11/05's UNIBUS.

	In the MASSBUS system, most device-specific [[register]]s (e.g. 'current [[cylinder]]' for disk drives) are actually in the device; the MASSBUS interface to the host computer only contains registers such as [[main memory]] transfer [[address]] and transfer word counts.		In the MASSBUS system, most device-specific [[register]]s (e.g. 'current [[cylinder]]' for disk drives) are actually in the device; the MASSBUS interface to the host computer only contains registers such as [[main memory]] transfer [[address]] and transfer word counts.
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	The first two and EXC are bi-directional; all the others are from entity to controller, except for WCLK and RUN.		The first two and EXC are bi-directional; all the others are from entity to controller, except for WCLK and RUN.

	==External link==		==External link==

	* [http://www.bitsavers.org/pdf/dec/standards/DEC_STD_159_Massbus_Specificaton.pdf DEC STD 159] - MASSBUS Specification		* [http://www.bitsavers.org/pdf/dec/standards/DEC_STD_159_Massbus_Specificaton.pdf DEC STD 159] - MASSBUS Specification

Jnc: /* Data Bus lines */ typo

2021-09-24T16:49:52Z

Data Bus lines: typo

← Older revision		Revision as of 16:49, 24 September 2021
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	The Data Bus contains the following signals:		The Data Bus contains the following signals:

	* Data Lines (D 0:18) - used to transfer data		* Data Lines (D 0:17) - used to transfer data
	* Data Lines Parity (DPA)		* Data Lines Parity (DPA)
	* Sync Clock (SCLK) - on write, a request from the entity for data to be sent; on read, notification from the entity that data is ready		* Sync Clock (SCLK) - on write, a request from the entity for data to be sent; on read, notification from the entity that data is ready

Jnc: /* Data Bus lines */ typo

2021-02-26T14:59:13Z

Data Bus lines: typo

← Older revision		Revision as of 14:59, 26 February 2021
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	The Data Bus contains the following signals:		The Data Bus contains the following signals:

	* Data Lines (D 0:18) - used to transfer ~~control~~ data		* Data Lines (D 0:18) - used to transfer data
	* Data Lines Parity (DPA)		* Data Lines Parity (DPA)
	* Sync Clock (SCLK) - on write, a request from the entity for data to be sent; on read, notification from the entity that data is ready		* Sync Clock (SCLK) - on write, a request from the entity for data to be sent; on read, notification from the entity that data is ready

Jnc: /* Data Bus lines */ DEC formal names

2021-02-25T08:22:37Z

Data Bus lines: DEC formal names

← Older revision		Revision as of 08:22, 25 February 2021
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	The Data Bus contains the following signals:		The Data Bus contains the following signals:

	* Data Lines 0:18 - used to transfer control data		* Data Lines (D 0:18) - used to transfer control data
	* Data Lines Parity		* Data Lines Parity (DPA)
	* Sync Clock - on write, a request from the entity for data to be sent; on read, notification from the entity that data is ready		* Sync Clock (SCLK) - on write, a request from the entity for data to be sent; on read, notification from the entity that data is ready
	* Write Clock - on write, notification from the controller that data is ready		* Write Clock (WCLK) - on write, notification from the controller that data is ready
	* Run - a signal from the controller to start a transfer		* Run (RUN) - a signal from the controller to start a transfer
	* End of Block - a signal from the entity to indicate the end of a transfer		* End of Block (EBL) - a signal from the entity to indicate the end of a transfer
	* Exception - a signal from the entity to indicate that an error has occurred during a transfer		* Exception (EXC) - a signal from the entity to indicate that an error has occurred during a transfer
	* Occupied - set by an entity to indicate that it is using the Data Bus		* Occupied (OCC) - set by an entity to indicate that it is using the Data Bus

			The first two and EXC are bi-directional; all the others are from entity to controller, except for WCLK and RUN.

	==External link==		==External link==

Jnc: /* Control Bus lines */ DEC formal names

2021-02-25T08:05:31Z

Control Bus lines: DEC formal names

← Older revision		Revision as of 08:05, 25 February 2021
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	The Control Bus contains the following signals:		The Control Bus contains the following signals:

	* Control Lines 0:15 - used to transfer control data		* Control Lines (C 0:15) - used to transfer control data
	* Control Lines Parity		* Control Lines Parity (CPA)
	* Drive Select 0:2 - selects the entity		* Drive Select (DS 0:2) - selects the entity
	* Register Select 0:4		* Register Select (RS 0:4)
	* Controller to Drive - direction of transfer		* Controller to Drive (CTOD) - direction of transfer
	* Demand - set by the controller to initiate a transfer		* Demand (DEM) - set by the controller to initiate a transfer
	* Transfer - acknowledgement from the entity		* Transfer (TRA) - acknowledgement from the entity
	* Attention - set by an entity to notify the controller		* Attention (ATTN) - set by an entity to notify the controller
	* Initialize - set by the controller		* Initialize (INIT) - set by the controller
	* ~~MASSBUS~~ Fail - set by the controller to indicate power loss		* Power Fail (FAIL) - set by the controller to indicate power loss

			The first two are bi-directional; all the others are from controller to entity, except for TRA and ATTN.

	===Data Bus lines===		===Data Bus lines===

Jnc: /* External link */ spec

2021-02-24T23:34:58Z

External link: spec

← Older revision		Revision as of 23:34, 24 February 2021
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	==External link==		==External link==

			* [http://www.bitsavers.org/pdf/dec/standards/DEC_STD_159_Massbus_Specificaton.pdf DEC STD 159] - MASSBUS Specification
	* [http://simh.trailing-edge.com/docs/massbusmystery.pdf A Massbus Mystery]		* [http://simh.trailing-edge.com/docs/massbusmystery.pdf A Massbus Mystery]

	[[Category: MASSBUS]]		[[Category: MASSBUS]]
	[[Category: DEC Buses]]		[[Category: DEC Buses]]