[Simh] single cycle stepping for pdp11

[Johnny Billquist]

On 2013-09-06 02:11, Doug Snyder wrote:
> do you have any examples of what you mean when you say "different models
> do different amounts of work in a single cycle"?

Look at 
http://bitsavers.informatik.uni-stuttgart.de/pdf/dec/pdp11/handbooks/PDP11_Handbook1979.pdf, 
appendix B.

Example:

     MOV (R0)+,(R1)+

11/34: 3 memory cycles
11/44: 2 memory cycles
11/60: 2 memory cycles
11/70: 2 memory cycles

I think most other smaller/slower machines all use 3 memory cycles, but 
I would suspect things like the J11 to also only use two memory cycles.

	Johnny

>
>
>
> On Thu, Sep 5, 2013 at 3:02 AM, Johnny Billquist <bqt at softjar.se
> <mailto:bqt at softjar.se>> wrote:
>
>     On 2013-09-05 07:15, Mark Pizzolato - Info Comm wrote:
>
>         On Wednesday, September 04, 2013 at 10:08 PM, Doug Snyder wrote:
>
>             it appears that simh supports single instruction stepping,
>             but not single cycle stepping for the pdp11.
>
>            >
>
>             if this is the case, have there been attempts or requests to
>             add single cycle support?
>
>
>         Hi Doug,
>
>         The core behaviors of the simh simulators are built around the
>         execution of instructions.  This is the level which things are
>         simulated at.
>
>         What problem are you trying to solve or deal with your request
>         to be concerned about clock cycles?
>
>
>     And even further - single cycle stepping will mean different things
>     on different models of the PDP-11. Or rather, different models do
>     different amounts of work in a single cycle.
>
>              Johnny
>
>     --
>     Johnny Billquist                  || "I'm on a bus
>                                        ||  on a psychedelic trip
>     email: bqt at softjar.se <mailto:bqt at softjar.se>             ||
>       Reading murder books
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>
>


-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol