T11 design WAS - Re: Inside old games machines, was: Re: Simulated CP/M-68K? - test-drb@ccmp.vtda.org

21 Jun 2007

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Subject: Re: T11 design WAS - Re: Inside old games machines,was: Re: Simulated CP/M-68K?
   From: woodelf <bfranchuk at jetnet.ab.ca>
   Date: Wed, 20 Jun 2007 22:18:57 -0600
     To: General Discussion: On-Topic and Off-Topic Posts <cctalk at
classiccmp.org>

Roger Ivie wrote:

  I don't know anything about the internals, so
I can't say. Although 
 AFAIK core was pretty much gone by the time the T-11 happened, it may 
 have been based on an earlier design that did interface to core. I think a read
modify write may have made Dynamic ram interface simpler.

No.

RMW was PDP11.  However some instructions would read, alter the value and write
it back.  Very useful for autoincrement addressing.

It also had to be that way to  be compatable with ALL previous PDP11s.

Allison