T11 design WAS - Re: Inside old games machines, was: Re: Simulated CP/M-68K?

[Allison]

>
>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