Re: A83: Direct Input/Delay

To: assembly-83@lists.ticalc.org
Subject: Re: A83: Direct Input/Delay
From: Jkhum98@aol.com
Date: Sun, 27 Sep 1998 19:09:06 EDT
Delivered-To: assembly-83-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-83@lists.ticalc.org



In a message dated 09/27/98 6:03:38 PM, oh@hem.passagen.se writes:

>Jkhum98@aol.com wrote:
>> 
>> Ok, (to add on to my mail a little bit) I just decided to experiment
>with some
>> delays, but it either froze my calc or is taking a helluva long time...
>:\
>> Tell me how much this delay sucks, and give me a new one please, anyone...?
>Im
>> not calling this in my Direct Input loop though. Its right after I switch
>the
>> text video of that word (like i was talking about before), and then calling
>> the Delay, and then jumping to my Direct Input loop. Whats the problem...?
>>                                                                     
>                                                                   --Jason K.
>> Delay:
>>         ld b, $FF
>> DelayLoop:
>>         push af
>>         dec b         <------ HERE!
>>         pop af
>>         nop
>>         djnz DelayLoop
>>         ret
>
>The problem is marked..   you start loading 255 in d (an odd number)  
>and in every loop you dec b twice before you test if its zero! once with
>the 'dec b' and one more time with the djnz.  the result is that b will
>never reach 0. because after each loop b will be an odd number.. (an
>even number subtracted from an an odd number will always result in an
>odd number) and as we all know, 0 is even..
>
>//Olle

Oh crap, your so right.  Damn... I just forgot that djnz does that for me
already, thanks Olle, and for helping even after the dispute I caused with the
thread of "A83: calls" mail... Well, Ill just take out that dec b then... =P
																--Jason K.