Olivetti M20

dwight elvey dkelvey at hotmail.com
Mon Jan 15 14:44:29 CST 2007




>From: Roger Holmes <roger.holmes at microspot.co.uk>
>
>On 15 Jan, 2007, at 18:00, cctalk-request at classiccmp.org wrote:
>
>>>Can anyone please tell me if the Olivetti M20 used a Z8010 memory
>>>management unit?
>>---snip---
>>
>>Hi Roger
>>No, it didn't use a 8010. It could have but I believe that when
>>the project was started, the 8010 wasn't ready yet.
>>They used a ROM instead. They do a number of interesting
>>logical to physical mapping but these could have been done
>>with a 8010 just as easily ( and more flexibly ).
>>Most of the mapping is to handle the holes that the video
>>causes. Some is related to the dual mapped memory.
>>Even with the full 512K of memory, I don't know of any
>>application that needed more than 384K.
>>Dwight
>
>
>
>Many thanks Dwight.
>
>A pity they did not at least use RAM instead of ROM.
>
>Roger.
>

Hi
It does block things as 16K chunks. To be RAM, it would have to
be fast but I guess any of those faster cache RAMs would do.
I believe the ROMs are 60 ns and I've seen the cache with
30 ns.
Dwight

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