FPJ11 floating point accelerator - Revision history

Jnc: Link to online copy

2026-09-02T13:17:54Z

Link to online copy

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	* [http://www.bitsavers.org/pdf/dec/internal/Semiconductor_Handbook_V1_1987.pdf DEC Semiconductor Databook, Volume 1], pp. 335-359		* [http://www.bitsavers.org/pdf/dec/internal/Semiconductor_Handbook_V1_1987.pdf DEC Semiconductor Databook, Volume 1], pp. 335-359
	* [http://www.bitsavers.org/pdf/dec/pdp11/1173/fpj11.txt FPJ11 Theory of Operation] μNote #040, 17 September 1985		* [http://www.bitsavers.org/pdf/dec/pdp11/1173/fpj11.txt FPJ11 Theory of Operation] [[MicroNote\|μNote]] #040, 17 September 1985
			* [https://www.ibiblio.org/pub/academic/computer-science/history/pdp-11/hardware/micronotes/numerical/micronote25.txt FPJ11-AA Compatibility with the LSI-11/73 (KDJ11-A)] μNote #025, 28 April 1985
	* [https://www.subgeniuskitty.com/development/pdp-11/references/fpj11_compat DCJ11/FPJ11 Compatibility]		* [https://www.subgeniuskitty.com/development/pdp-11/references/fpj11_compat DCJ11/FPJ11 Compatibility]

	==Further reading==		<!-- ==Further reading== -->

	* μNote #025, "FPJ11-AA Compatibility with the LSI-~~11/73 (KDJ11~~-~~A)", 28 April 1985~~

	[[Category: PDP-11 Processors]]		[[Category: PDP-11 Processors]]

Jnc: rm bloat

2023-07-02T19:06:51Z

rm bloat

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	* μNote #025, "FPJ11-AA Compatibility with the LSI-11/73 (KDJ11-A)", 28 April 1985		* μNote #025, "FPJ11-AA Compatibility with the LSI-11/73 (KDJ11-A)", 28 April 1985

	~~{{PDP-11}}~~

	[[Category: PDP-11 Processors]]		[[Category: PDP-11 Processors]]

Vaxorcist: Fixed typo

2023-06-03T20:30:32Z

Fixed typo

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	Although the DCJ11 contains a full implementation of the FP11 floating point [[instruction]]s, in [[microcode]], if a J-11 CPU board has an FPJ11 installed, the DCJ111 will automatically notice the presence of the FPJ11, and allow it to handle all floating-point instructions.		Although the DCJ11 contains a full implementation of the FP11 floating point [[instruction]]s, in [[microcode]], if a J-11 CPU board has an FPJ11 installed, the DCJ111 will automatically notice the presence of the FPJ11, and allow it to handle all floating-point instructions.

	Addition of the FPJ11 improves floating-point ~~peformance~~ by a factor of 5 to 8. The interface between the DCJ11 and the FPJ11 is designed to allow overlap between execution of floating point instructions in the FPJ11, and execution of non-floating point instructions in the DCJ11.		Addition of the FPJ11 improves floating-point performance by a factor of 5 to 8. The interface between the DCJ11 and the FPJ11 is designed to allow overlap between execution of floating point instructions in the FPJ11, and execution of non-floating point instructions in the DCJ11.

	==Versions==		==Versions==

Jnc: /* External links */ typo

2022-04-24T11:42:09Z

External links: typo

← Older revision		Revision as of 11:42, 24 April 2022
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	* [http://www.bitsavers.org/pdf/dec/internal/Semiconductor_Handbook_V1_1987.pdf DEC Semiconductor Databook, Volume 1], pp. 335-359		* [http://www.bitsavers.org/pdf/dec/internal/Semiconductor_Handbook_V1_1987.pdf DEC Semiconductor Databook, Volume 1], pp. 335-359
	* [http://www.bitsavers.org/pdf/dec/pdp11/1173/fpj11.txt FPJ11 Theory of Operation] μNote #040, 17 September 1985		* [http://www.bitsavers.org/pdf/dec/pdp11/1173/fpj11.txt FPJ11 Theory of Operation] μNote #040, 17 September 1985
	* [https://www.subgeniuskitty.com/development/pdp-11/references/fpj11_compat ~~DJC11~~/FPJ11 Compatibility]		* [https://www.subgeniuskitty.com/development/pdp-11/references/fpj11_compat DCJ11/FPJ11 Compatibility]

	==Further reading==		==Further reading==

Jnc: /* External links */ +DJC11/FPJ11 Compatibility

2022-03-16T11:59:56Z

External links: +DJC11/FPJ11 Compatibility

← Older revision		Revision as of 11:59, 16 March 2022
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	* [http://www.bitsavers.org/pdf/dec/internal/Semiconductor_Handbook_V1_1987.pdf DEC Semiconductor Databook, Volume 1], pp. 335-359		* [http://www.bitsavers.org/pdf/dec/internal/Semiconductor_Handbook_V1_1987.pdf DEC Semiconductor Databook, Volume 1], pp. 335-359
	* [http://www.bitsavers.org/pdf/dec/pdp11/1173/fpj11.txt FPJ11 Theory of Operation] μNote #040, 17 September 1985		* [http://www.bitsavers.org/pdf/dec/pdp11/1173/fpj11.txt FPJ11 Theory of Operation] μNote #040, 17 September 1985
			* [https://www.subgeniuskitty.com/development/pdp-11/references/fpj11_compat DJC11/FPJ11 Compatibility]

	==Further reading==		==Further reading==

Jnc: link μ"

2021-11-23T12:31:01Z

link μ"

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	* [http://www.bitsavers.org/pdf/dec/internal/Semiconductor_Handbook_V1_1987.pdf DEC Semiconductor Databook, Volume 1], pp. 335-359		* [http://www.bitsavers.org/pdf/dec/internal/Semiconductor_Handbook_V1_1987.pdf DEC Semiconductor Databook, Volume 1], pp. 335-359
			* [http://www.bitsavers.org/pdf/dec/pdp11/1173/fpj11.txt FPJ11 Theory of Operation] μNote #040, 17 September 1985

	==Further reading==		==Further reading==

	* ~~uNote~~ #025, "FPJ11-AA Compatibility with the LSI-11/73 (KDJ11-A)", 28 April ~~1985~~		* μNote #025, "FPJ11-AA Compatibility with the LSI-11/73 (KDJ11-A)", 28 April 1985
	* uNote #040, "FPJ11 Theory of Operation", 17 September 1985

	{{PDP-11}}		{{PDP-11}}

	[[Category: PDP-11 Processors]]		[[Category: PDP-11 Processors]]

Jnc: /* External links */ +detailed spec

2021-03-29T00:39:58Z

External links: +detailed spec

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	Two versions of the FPJ11 exist; the FPJ11-AA and the FPJ11-AB. DEC had a number of problems with 'corner cases' (e.g. [[Direct Memory Access\|DMA]] during certain floating point instructions), and had to issue revised versions of the FPJ11 and some J-11 CPU boards (e.g. the [[KDJ11-A CPU\|KDJ11-A]]) to fix them all.		Two versions of the FPJ11 exist; the FPJ11-AA and the FPJ11-AB. DEC had a number of problems with 'corner cases' (e.g. [[Direct Memory Access\|DMA]] during certain floating point instructions), and had to issue revised versions of the FPJ11 and some J-11 CPU boards (e.g. the [[KDJ11-A CPU\|KDJ11-A]]) to fix them all.

			==External links==

			* [http://www.bitsavers.org/pdf/dec/internal/Semiconductor_Handbook_V1_1987.pdf DEC Semiconductor Databook, Volume 1], pp. 335-359

	==Further reading==		==Further reading==

Jnc: add image

2020-01-05T20:43:06Z

add image

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	The '''FPJ11 floating point accelerator''' is an optional [[floating point]] [[co-processor]] for the DCJ11 [[J-11 chip set\|J-11]] [[PDP-11]] chip, which implements the full [[FP11 floating point]] [[instruction set]]. The FPJ11 is a single ~~[[integrated circuit\|~~chip]] which is plugged into a socket on a ~~J-11~~ [[~~Central Processing Unit~~\|CPU]] card.		[[Image:FPJ11.jpg\|250px\|thumb\|right\|FPJ11 chip (plugged into [[KDJ11-A CPU]])]]

			The '''FPJ11 floating point accelerator''' is an optional [[floating point]] [[co-processor]] for the DCJ11 [[J-11 chip set\|J-11]] [[PDP-11]] [[Central Processing Unit\|CPU]] [[integrated circuit\|chip]], which implements the full [[FP11 floating point]] [[instruction set]]. The FPJ11 is a single chip which is plugged into a [[chip socket\|socket]] on a [[KDJ11 CPUs\|KDJ11 CPU]] card.

	Although the DCJ11 contains a full implementation of the FP11 floating point [[instruction]]s, in [[microcode]], if a J-11 CPU board has an FPJ11 installed, the DCJ111 will automatically notice the presence of the FPJ11, and allow it to handle all floating-point instructions.		Although the DCJ11 contains a full implementation of the FP11 floating point [[instruction]]s, in [[microcode]], if a J-11 CPU board has an FPJ11 installed, the DCJ111 will automatically notice the presence of the FPJ11, and allow it to handle all floating-point instructions.

Jnc: better cat

2018-12-16T21:59:24Z

better cat

← Older revision		Revision as of 21:59, 16 December 2018
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	{{PDP-11}}		{{PDP-11}}

	[[Category: ~~DEC~~ Processors]]		[[Category: PDP-11 Processors]]

Jnc: +cat

2018-12-16T04:11:16Z

+cat

← Older revision		Revision as of 04:11, 16 December 2018
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	{{PDP-11}}		{{PDP-11}}

			[[Category: DEC Processors]]