Re: A86: a question


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Re: A86: a question






Jared Ivey wrote:

> >Could someone please explain what "T states" mean
> >in relation to Z80 processor speed?  I looked it
> >up in the Z80 reference book from Zilog, but it
> >didn't explain it.
>
> T states is short for time states.  I don't know exactly how long a T
> state is, but you don't really need to.  Think of it more as a ratio of
> time...
>    ie: ex  de,hl   ;4  T states
>        add ix,de   ;15 T states
>    the ratio  exDE,hl:addIX,de is
>    4:15 or 1 to 3.75
>
> When determining the most time efficient routine, you don't need to
> consider the actual time, only the ratio of time states (both ratios are
> equivalent).  About the only time you might need to consider actual time
> is if you were writing a clock program, or timer in a game, etc...
>

You were right the first time...  1.5 million times a second seems like a
lot, but it's not really...  think about all your computer does in a
second...  my new web page explains it a
littlehttp://www.mindspring.com/~shicks/ti86/

> >Lastly, the R (dynamic memory refresh)...
> >Is this why..."random" numbers?
>
> I believe that is correct.
>

each interrupt increments r by 2 i think (not sure), otherwise, each command
executed increments it by 2.

> Sincerely,
> The Unibomer
>
> Jared Ivey
> Unibomer@Juno.com
> http://www.geocities.com/SiliconValley/Vista/7342
>
> "Bill my Friend, something very strange is a foot at the Circle K." --
> Bill and Ted's Excellent Adventure
>
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--
Stephen Hicks
mailto:shicks@mindspring.com
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