Difference between revisions of "MG10 core memory"
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| − | The '''MG10''' was a [[core memory|core]] [[main memory]] system for the [[PDP-10]]s, principally the early [[KL10]]. An MG10 could contain up to four 32KW memory banks, for a maximum of 128KW | + | The '''MG10''' was a [[core memory|core]] [[main memory]] system for the [[PDP-10]]s, principally the [[KI10]] and early [[KL10]]s. An MG10 could contain up to four 32KW memory banks, for a maximum of 128KW (only 1, 2 or 4 bank operation is supported, however). The [[access time]] is .67 μseconds maximum, and the [[cycle time]] is 1.0 μseconds; [[parity]] is provided to protect the memory contents. An MG10 contains a pair of 'controllers', with the controller used for any particular cycle selected by [[address]] bit 21. |
| − | It was a [[multi-port memory]], with 8 ports per memory system: the [[Central Processing Unit|CPU]] uses one port (in a [[multi-processor]] system, one per CPU); the others are used by | + | It was a [[multi-port memory]], with 8 ports per memory system: the [[Central Processing Unit|CPU]] uses at least one port (in a [[multi-processor]] system, at least one per CPU); the others are used by [[channel]]s (such as a [[DF10 Data Channel|DF10]]) for [[mass storage]] such as [[disk]]s. |
| − | It connected to the so-called external memory bus of the 18-or 22-bit address form. Each port | + | It connected to the so-called [[PDP-10 Memory Bus|external memory bus]] of the KA (18-bit address) or KI (22-bit address) form. Each port could be independently set to use 18- or 22-bit addresses, or to be disabled. The base address of an MG10 is switch-selectable; that address is used on all the ports, unlike the earlier [[PDP-10 memories]]. |
| − | The | + | The MG10 supports two-way [[memory interleaving|interleaving]] internally to an MG10, and four-way interleaving between a pair of MG10's (provided they are equally sized); any interleaving applies to all ports. For the two-way case, address bits 21 and 35 are exchanged (recall that the PDP-10 uses [[big-endian]] numbering, so bit 35 is the low-order bit), so that all even addresses are handled by controller 0, and odd through controller 1. |
| − | [[Category: PDP-10 | + | The MG10 shares components with the [[MM11-U core memory]] of the [[PDP-11]]: the G114 sense/inhibit and G235 XY Drive cards; and the H217-B core plane of the MG10 is a 19-bit version of the 18-/16-bit H217-C/D of the MM11-U. |
| + | |||
| + | ==External links== | ||
| + | |||
| + | * [http://www.bitsavers.org/pdf/dec/pdp10/memory/EK-MG10-MM-001_MG10_Maintenance_Manual.pdf MG10 Maintenance Manual] (EK-MG10-MM-001) | ||
| + | * [http://www.bitsavers.org/pdf/dec/pdp10/memory/MG10_Schematic_Jun75.pdf MG10 Engineering Drawings] | ||
| + | |||
| + | [[Category: PDP-10 Memories]] | ||
Latest revision as of 11:33, 5 November 2023
The MG10 was a core main memory system for the PDP-10s, principally the KI10 and early KL10s. An MG10 could contain up to four 32KW memory banks, for a maximum of 128KW (only 1, 2 or 4 bank operation is supported, however). The access time is .67 μseconds maximum, and the cycle time is 1.0 μseconds; parity is provided to protect the memory contents. An MG10 contains a pair of 'controllers', with the controller used for any particular cycle selected by address bit 21.
It was a multi-port memory, with 8 ports per memory system: the CPU uses at least one port (in a multi-processor system, at least one per CPU); the others are used by channels (such as a DF10) for mass storage such as disks.
It connected to the so-called external memory bus of the KA (18-bit address) or KI (22-bit address) form. Each port could be independently set to use 18- or 22-bit addresses, or to be disabled. The base address of an MG10 is switch-selectable; that address is used on all the ports, unlike the earlier PDP-10 memories.
The MG10 supports two-way interleaving internally to an MG10, and four-way interleaving between a pair of MG10's (provided they are equally sized); any interleaving applies to all ports. For the two-way case, address bits 21 and 35 are exchanged (recall that the PDP-10 uses big-endian numbering, so bit 35 is the low-order bit), so that all even addresses are handled by controller 0, and odd through controller 1.
The MG10 shares components with the MM11-U core memory of the PDP-11: the G114 sense/inhibit and G235 XY Drive cards; and the H217-B core plane of the MG10 is a 19-bit version of the 18-/16-bit H217-C/D of the MM11-U.
External links
- MG10 Maintenance Manual (EK-MG10-MM-001)
- MG10 Engineering Drawings
