MM11-Y core memory - Revision history

Jnc: interleaving cleanup

2023-07-29T22:47:02Z

interleaving cleanup

Jnc: /* External links */ rm extraneous nav panel

2022-06-03T21:52:47Z

‎External links: rm extraneous nav panel

Jnc: +link

2022-06-03T15:53:23Z

+link

Jnc: typo

2021-10-01T13:48:23Z

typo

Jnc: Emphasize formal name

2021-10-01T13:47:29Z

Emphasize formal name

Jnc: Complete the set

2021-10-01T12:40:27Z

Complete the set

New page

The '''MM11-Y''' was a 64 Kbyte [[core memory|core]] [[main memory]] for [[PDP-11]] [[UNIBUS]] machines. An MM11-Y was composed of two [[DEC card form factor‎|hex]] boards, one piggy-backed on the other, and the pair taking only a single [[backplane]] slot (electrically):

* An H228-B daughter-board containing the cores
* A G657 mother-board containing most of the electronics, and the contact fingers for plugging into a backplane

The MM11-Y did not use a custom backplane; it plugged into a standard [[Modified UNIBUS Device|MUD slot]]. The pair was 'thick' enough that a normal board cannot be plugged into the next slot; instead, a [[G727 grant continuity card]] must be used there (since it has no components on it, it just clears the H228-B card).

It provided [[parity]], so technically its name was '''MM11-DP'''; it used an [[M7850 parity controller]] plugged into the same backplane as the MM11-D. The core array provided two more bits per [[word]], to support [[byte]] parity..

It is possible to [[interleave]] a pair of MM11-Y's to provide reduced effective average [[access time]]s.

==Further reading==

* ''MM11-YP User's Manual'' (EK-MM1YP-UG) - not available online
* ''MM11-YP Technical Manual'' (EK-MM1YP-TM-001) - not available online, exists in fiche

==External links==

* [https://deramp.com/downloads/mfe_archive/011-Digital%20Equipment%20Corporation/08%20PDP-11/05%20Unibus%20Options/MM11-YP%20G657%20M7850%2032K%20x%2018%20Core%20Memory/ MM11-YP Memory Module Field Maintenance Print Set] (MP-00317)

{{PDP-11}}

[[Category: UNIBUS Memories]]

@@ Line 10: / Line 10: @@
 The core array provided two more bits per [[word]], to support [[byte]] parity; parity operation used an [[M7850  parity controller]] plugged into the same backplane as the MM11-D.
-It is possible to [[interleave]] a pair of MM11-Y's to provide reduced effective average [[access time]]s.
+It is possible to [[memory interleaving|interleave]] a pair of MM11-Y's to provide reduced effective average [[access time]]s.
 ==Further reading==

← Older revision		Revision as of 21:52, 3 June 2022
Line 20:		Line 20:

	* [https://deramp.com/downloads/mfe_archive/011-Digital%20Equipment%20Corporation/08%20PDP-11/05%20Unibus%20Options/MM11-YP%20G657%20M7850%2032K%20x%2018%20Core%20Memory/ MM11-YP Memory Module Field Maintenance Print Set] (MP-00317)		* [https://deramp.com/downloads/mfe_archive/011-Digital%20Equipment%20Corporation/08%20PDP-11/05%20Unibus%20Options/MM11-YP%20G657%20M7850%2032K%20x%2018%20Core%20Memory/ MM11-YP Memory Module Field Maintenance Print Set] (MP-00317)
−
−	~~{{PDP-11}}~~

	[[Category: UNIBUS Memories]]		[[Category: UNIBUS Memories]]

← Older revision		Revision as of 13:48, 1 October 2021
Line 1:		Line 1:
−	The '''MM11-Y''' was a 64 Kbyte [[core memory\|core]] [[main memory]] for [[PDP-11]] [[UNIBUS]] machines. It provided [[parity]], so its formal name was '''MM11-DP'''.	+	The '''MM11-Y''' was a 64 Kbyte [[core memory\|core]] [[main memory]] for [[PDP-11]] [[UNIBUS]] machines. It provided [[parity]], so its formal name was '''MM11-YP'''.

	An MM11-Y was composed of two [[DEC card form factor‎\|hex]] boards, one piggy-backed on the other, and the pair taking only a single [[backplane]] slot (electrically):		An MM11-Y was composed of two [[DEC card form factor‎\|hex]] boards, one piggy-backed on the other, and the pair taking only a single [[backplane]] slot (electrically):

@@ Line 3: / Line 3: @@
 An MM11-Y was composed of two [[DEC card form factor‎|hex]] boards, one piggy-backed on the other, and the pair taking only a single [[backplane]] slot (electrically):
-* An H228-B daughter-board containing the cores
+* An H228-B [[daughter-board]] containing the cores
 * A G657 mother-board containing most of the electronics, and the contact fingers for plugging into a backplane

@@ Line 1: / Line 1: @@
-The '''MM11-Y''' was a 64 Kbyte [[core memory|core]] [[main memory]] for [[PDP-11]] [[UNIBUS]] machines. An MM11-Y was composed of two [[DEC card form factor‎|hex]] boards, one piggy-backed on the other, and the pair taking only a single [[backplane]] slot (electrically):
+The '''MM11-Y''' was a 64 Kbyte [[core memory|core]] [[main memory]] for [[PDP-11]] [[UNIBUS]] machines. It provided [[parity]], so its formal name was '''MM11-DP'''.
 * An H228-B daughter-board containing the cores
@@ Line 6: / Line 8: @@
 The MM11-Y did not use a custom backplane; it plugged into a standard [[Modified UNIBUS Device|MUD slot]]. The pair was 'thick' enough that a normal board cannot be plugged into the next slot; instead, a [[G727 grant continuity card]] must be used there (since it has no components on it, it just clears the H228-B card).
-It provided [[parity]], so technically its name was '''MM11-DP'''; it used an [[M7850  parity controller]] plugged into the same backplane as the MM11-D. The core array provided two more bits per [[word]], to support [[byte]] parity..
+The core array provided two more bits per [[word]], to support [[byte]] parity; parity operation used an [[M7850  parity controller]] plugged into the same backplane as the MM11-D.
 It is possible to [[interleave]] a pair of MM11-Y's to provide reduced effective average [[access time]]s.