Re: A82: Re: Game Speed

To: <assembly-82@lists.ticalc.org>
Subject: Re: A82: Re: Game Speed
From: "Dines Justesen" <dines@resnet.gatech.edu>
Date: Wed, 18 Nov 1998 23:54:38 -0500
Delivered-To: assembly-82-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-82@lists.ticalc.org


Setting the interrupt speed to TURBO will not speed up the call to GET_KEY,
but it will make GET_KEY detect keys faster. The reason for this is that the
build in interrupt routine checks all the keys, if one is pressed the number
of it is stored in the buffer. When you call GET_KEY all the calc does is to
read from the buffer. Since interrupts are called more often, key presses
will be detected faster. Another way to get the same results could be to
call the function which detects the keys directly, but I don't know if that
is possible (maybe it contains a JP).

Dines

BTW unless you are using all the keys on the TI82, accessing the keypad port
directly should be faster, and it is not very hard to do.

----- Original Message -----
From: <evil.sam@mailexcite.com>
To: <assembly-82@lists.ticalc.org>
Sent: Wednesday, November 18, 1998 9:29 PM
Subject: Re: A82: Re: Game Speed


>
>> 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.
>
>  From what I tried, certain ROM_CALL's are sped up significantly. The most
>noticeable one being "GET_KEY". I'm using Turbo mode in Ztetris to speed up
>key press detection, then removing it when the game is over. No apparent
>side effects have occured when tested under ROM 18 and 19.
>
>
>
>
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