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23 lines
1.2 KiB
Markdown
23 lines
1.2 KiB
Markdown
## Known differences between w11a and KB11-C (11/70)
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### No cache parity and minimal subset of memory system controls
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The 11/70 provides extensive reliability and diagnostics features for the cache
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and memory system. They are very specific to the concrete 11/70 implementation
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and most can't be mapped to the w11 implementation. The w11 provides all
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the cache and memory system control registers, but provides only a very
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limited subset of the functionality:
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- no cache parity, and therefore no vector 114 interrupts
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- the cache hit/miss and memory size registers are implemented
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- 177752 memory system hit/miss register: gives hit/miss for last 6 accesses
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- 177760 memory system lower size register: gives size in clicks
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- the memory system control register (177746) has limited functionality
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- the cache can be disabled, setting bit 2 or bit 3 will force a cache miss
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- bits 0,1,4, and 5 can be set and read back, but have no function
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- the following registers return zero on reads and ignore writes
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- 177740 low error address register
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- 177742 high error address register
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- 177744 memory system errior register
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- 177750 memory system maintenance register
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- 177762 memory system upper size register
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