Re: A82: Re: Game Speed
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Re: A82: Re: Game Speed
inside
In a message dated 11/15/98 2:34:39 PM Eastern Standard Time,
dines@resnet.gatech.edu writes:
> Normally setting the interrupts to its fastest wont increase the speed of
> your game, since this increses th enumber of clock cycles spend on
> interrupts, but if you need faster interrupts this is definately a way to
do
> it.
>
> I do not think any one has look at what happens when you change the
> interrupt speed of the calc, so you can be 100% sure of what happens.
> However based on the discription of the display controller, this is what I
> think happens.
>
> The display controller has two inputs which are used to control the
> frequency used to update the display (FS1 and FS2). Writing to port 4 sets
> these two values, there by affecting the frequency of the display
> controller. One of the output of the display controller is normally used to
> control the speed of other controllers (slaves), this output is connected
to
> the interrupt lines on the TI82. So changing the interrupt speeds will make
> the display controller use a faster frequency, and give faster interrupts.
I guess this is a good explanation of why grayscale quality varies so
drastically with each interrupt mode...
>
> What effect the faster frequency has on the display controller is unknow,
> but you will probably ba able to use it as normal.
>
> The CrASH people once claimed that using TURBO mode will mess up your ti82,
> and the only solution was to reset the calc. I have however seen no
evidence
> of this, and I think the problem was that they where sending data to the
> controller too fast, while it was running on the high frequency.
well, they said that you calc will "remember" (in the simplest explaination)
that it was once turboed and when you unturbo it it will get back at you :-).
then they discovered that setting it to "normal" wasn't really normal and you
had to add a bit somewhere or something like that. I forget.
>
> To test how the controller works in turbo mode, try to see if you can see
> any difference in how long time the busy flag is set in normal and fast
> operation. Based on this you can see if you can make your graphics routines
> faster, or whether they have to be slowed down.
>
> I do not think that you should have any problems using the fastest possible
> interrupt mode, so if you need it in your game use it. However before
> releasing it it would probably be a good idea to do test your program on
> several different calcs, to make sure that it works.
>
> Dines
~Adamman