QBUS memories - Revision history

Jnc: /* External links */ original at Frain Research went offline; add reference to online mirror

2025-05-30T13:35:46Z

‎External links: original at Frain Research went offline; add reference to online mirror

Jnc: make link visible

2024-07-25T14:35:17Z

make link visible

Jnc: /* Further reading */ +Configuring Memory for LSI-11 Systems with More Than 64K Bytes

2024-07-25T13:38:07Z

‎Further reading: +Configuring Memory for LSI-11 Systems with More Than 64K Bytes

Glitch: Adding Monolithic Systems QBus MOS memories

2024-07-19T19:01:16Z

Adding Monolithic Systems QBus MOS memories

Jnc: Avoid dab

2022-09-20T00:21:02Z

Avoid dab

Jnc: +links

2022-08-06T11:53:34Z

+links

Jnc: /* Diagnosing DRAM memory failures */ clarify

2022-08-06T11:45:26Z

‎Diagnosing DRAM memory failures: clarify

Jnc: /* MOS memory */ typo

2022-08-02T22:27:33Z

‎MOS memory: typo

Jnc: /* DEC */ +MSV11-A

2022-08-02T20:24:50Z

‎DEC: +MSV11-A

Jnc: /* MOS memory */ avoid redir

2021-02-08T03:41:29Z

‎MOS memory: avoid redir

@@ Line 141: / Line 141: @@
 ==External links==
-* [http://web.frainresearch.org:8080/projects/pdp-11/memory.php Read/Write Memory Modules]
+* [http://web.frainresearch.org:8080/projects/pdp-11/memory.php Read/Write Memory Modules] (mirrored [https://electrickery.nl/comp/pdp11_23plus/frain.rsx11m.io/memory.php here])
 [[Category: QBUS Memories]]
 [[Category: DEC Memories]]

← Older revision		Revision as of 14:35, 25 July 2024
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−	'''[[QBUS]] memory''' cards are available both from [[Digital Equipment Corporation\|DEC]], and from a large number of outside vendors who produced and sold QBUS [[main memory]] cards.	+	'''QBUS memory''' cards are available both from [[Digital Equipment Corporation\|DEC]], and from a large number of outside vendors who produced and sold [[QBUS]] [[main memory]] cards.

	Like the QBUS itself, QBUS memory cards can be divided into [[QBUS#Variable address size\|Q16]], Q18 and Q22 memories. In addition, DEC later specified the [[Private Memory Interconnect\|PMI]] memory bus, an extension of the QBUS, and some memory cards have dual QBUS/PMI capability.		Like the QBUS itself, QBUS memory cards can be divided into [[QBUS#Variable address size\|Q16]], Q18 and Q22 memories. In addition, DEC later specified the [[Private Memory Interconnect\|PMI]] memory bus, an extension of the QBUS, and some memory cards have dual QBUS/PMI capability.

@@ Line 134: / Line 134: @@
 * [[PMI memories]]
 * [[Repairing un-documented MOS memory boards]]
 ==External links==

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 * [[QED1]] (aka QED-F) - 2-Mbyte / 4-Mbyte
 * [[DCME-Q4E]] - 2-Mbyte / 4-Mbyte
 ==Mostek==

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 * [[MSV11-A static MOS memory|MSV11-A]] - 2-Kbyte ([[static RAM]])
-* [[MSV11-B MOS memory|MSV11-B]] - 8-Kbyte (external [[refresh]] - M7944)
+* [[MSV11-B MOS memory|MSV11-B]] - 8-Kbyte (external [[memory refresh|refresh]] - M7944)
 * [[MSV11-C MOS memory|MSV11-C]] - (on-board refresh - M7955)
 ** MSV11-CA - 8-Kbyte

@@ Line 5: / Line 5: @@
 ==Using Q18 memory in Q22 machines==
-Note that although Q18 memory cards can be plugged into a Q22 machine (e.g. most 11/23's, and all 11/73's), and seem to work, they will not always function properly, and may cause subtle errors. (The sole exception to this rule is in machines with less than 256KB memory, total.)
+Note that although Q18 memory cards can be plugged into a Q22 machine (e.g. most [[PDP-11/23]]'s, and all [[PDP-11/73|-11/73]]'s), and seem to work, they will not always function properly, and may cause subtle errors. (The sole exception to this rule is in machines with less than 256KB memory, total.)
 This is because a Q18 memory configured for 000000 and up will also respond to bus cycles to 01000000 and up, 02000000 and up, etc.
@@ Line 11: / Line 11: @@
 ==Diagnosing DRAM memory failures==
-If a memory card has multiple banks of chips (e.g. a board built with 64Kx1 chips, so that with the need for a minimum of 16 chips to produce word-wide memory, if it has 32 chips, or two complete banks, for a total capacity of 256KB), and one bank is picking or dropping bit(s), and the other(s) is/are not, that meant that [[data path]]s are all OK, and it is a simple matter of finding the bad memory chip(s).
+If a memory card has multiple banks of [[integrated circuit|chips]] (e.g. a board built with 64Kx1 chips, so that with the need for a minimum of 16 chips to produce [[word]]-wide memory, if it has 32 chips, or two complete banks, for a total capacity of 256KB), and one bank is picking or dropping bit(s), and the other(s) is/are not, that meant that [[data path]]s are all OK, and it is a simple matter of finding the bad memory chip(s).
-This diagnostic heuristic is quite useful, since many PDP-11 semiconductor memory cards have (because of the logical size of [[Dynamic RAM|DRAM]] chips, and QBUS cards) two or more banks of nnKx1 chips; so if such a memory card has dropped/picked bits, look to see if all banks have the same fault. If 'no', it's pretty much guaranteed to be a memory chip, and it should be easy to find and fix.
+This [[diagnostic]] heuristic is quite useful, since many QBUS semiconductor memory cards have (because of the storage size of [[Dynamic RAM|DRAM]] chips, and QBUS cards) two or more banks of nnKx1 chips; so if such a memory card has dropped/picked bits, look to see if all banks have the same fault. If 'no', it's pretty much guaranteed to be a memory chip, and it should be easy to find and fix.
 It is possible to repair memory cards with this failure mode without doing any hardware debugging at all; the symptoms, and the memory chip layout (given in the pages for many of the cards listed below), are all one needs. See [[Repairing un-documented MOS memory boards]] for more.

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 ===Core memory===
-* [[MMV11-A]] - 8-Kbyte unit (H653 and H223)
+* [[MMV11-A QBUS core memory|MMV11-A]] - 8-Kbyte unit (H653 and H223)
 ===MOS memory===
-* [[MSV11-B]] - 8-Kbyte (external [[refresh]] - M7944)
+* [[MSV11-A static MOS memory|MSV11-A]] - 8-Kbyte ([[static RAM]])
-* [[MSV11-C]] - (on-board refresh - M7955)
+* [[MSV11-B MOS memory|MSV11-B]] - 8-Kbyte (external [[refresh]] - M7944)
 ** MSV11-CA - 8-Kbyte
 ** MSV11-CB - 16-Kbyte

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 ** MSV11-CC - 24-Kbyte
 ** MSV11-CD - 32-Kbyte
-* [[MSV11-D MOS memory|MSV11-D]] - (no [[parity]] - M8044)
+* [[MSV11-D/E MOS memory|MSV11-D]] - (no [[parity]] - M8044)
 ** MSV11-DA - 8-Kbyte
 ** MSV11-DB - 16-Kbyte
 ** MSV11-DC - 32-Kbyte
 ** MSV11-DD - 64-Kbyte
-* [[MSV11-D MOS memory|MSV11-E]] - (parity - M8045)
+* [[MSV11-D/E MOS memory|MSV11-E]] - (parity - M8045)
 ** MSV11-EA - 8-Kbyte
 ** MSV11-EB - 16-Kbyte