Difference between revisions of "MS750 Memory System"

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(add image of backplane, showing memory slots - explain division between memory and CPU slots)
m (External links: +M8750 eng drws)
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* [http://www.bitsavers.org/pdf/dec/vax/750/EK-MS750-TD-001_VAX-11_750_Memory_System_Technical_Description_198009.pdf VAX-11/750 Memory System Technical Description] (EK-MS750-TD-001)
 
* [http://www.bitsavers.org/pdf/dec/vax/750/EK-MS750-TD-001_VAX-11_750_Memory_System_Technical_Description_198009.pdf VAX-11/750 Memory System Technical Description] (EK-MS750-TD-001)
 
* [http://www.bitsavers.org/pdf/dec/vax/750/MP01404_750_Engineering_Drawings_Memory_Controller_198206.pdf Comet Memory Unit Field Maintenance Print Set] (MP01404) - covers the L0016
 
* [http://www.bitsavers.org/pdf/dec/vax/750/MP01404_750_Engineering_Drawings_Memory_Controller_198206.pdf Comet Memory Unit Field Maintenance Print Set] (MP01404) - covers the L0016
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* [http://www.bitsavers.org/pdf/dec/vax/730/MP01270_11-730_Engineering_Drawings_198204.pdf 11/730-Z Field Maintenance Print Set (MP01270)] - the M8750 is covered in MS730-C Field Maintenance Print Set (MP01366) (pp. 292-12 of the PDF)
  
 
[[Category: VAXen]]
 
[[Category: VAXen]]
 
[[Category: DEC Memories]]
 
[[Category: DEC Memories]]

Revision as of 23:26, 2 June 2022

/750 backplane from behind, showing the slots occupied by the MS750 in the centre

The MS750 Memory System is the main memory for the VAX-11/750; it consists of:

  • one Memory Controller (MCM)
  • one to eight Memory Modules

The Memory Controller connects to the CPU/Memory Interconnect bus; the Controller Module (either L0011, L0016, or L0022) resides in a custom slot in the CPU backplane, slot 10.

The Memory Modules have their own backplane slots (the physical backplane itself, DEC part number 50-13821/70-16486, is shared with the CPU), 8 slots in total.

VAX-11/750 Memory Controllers

256KB module

There were three different Memory Controller Modules for the MS750:

  • L0011 - up to eight M8728 256KB Memory Modules = 2MB max.
  • L0016 - up to eight M8750 1MB Memory Modules = 8MB max.
  • L0022 - up to two M7199 4MB Memory Modules and six M8750 1MB Memory Modules = 14MB max.

(14MB of Memory is the architectural limit of the VAX-11/750)

1MB module


The earlier modules are also used with the MK11 memory system of the PDP-11/70.

External links