Re: A83: Re: SpRiTes ?


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Re: A83: Re: SpRiTes ?




Oh, sorry.  I forget that the 82/83 have a display controller.  If you move
sprites too fast, they will flicker no matter what you do.  This is because
the display is slow.  Even on the 86, which has a high-quality memory-mapped
display, sprites flicker if they move really fast.

-----Original Message-----
From: Linus Akesson <lairfight@softhome.net>
To: David Phillips <assembly-83@lists.ticalc.org>
Date: Friday, October 23, 1998 2:26 PM
Subject: Re: A83: Re: SpRiTes ?


>
>True, but there _isn't_ any video ram on the 83! The virtual screen is
>actually plotsscreen. Then when you call grbufcpy_v, that buffer is copied
to
>the display. So for some reason, this guy must be doing several
intermediate
>calls to grbufcpy_v.
>
>Linus
>
>On 22-Oct-98, David Phillips wrote:
>
>>Two words:  Virtual Screen
>
>>A virtual screen is an off-screen buffer that is the same size as the
>>screen.  You draw all of your sprites there, then you dump the virtual
>>screen to video memory using a LDIR instruction when you are done drawing
>>all of them:
>
>>ld hl,VirtScr
>>ld de,VIDEO_RAM
>>ld bc,768
>>ldir
>
>>-----Original Message-----
>>From: yean yean <yhean@mailcity.com>
>>To: assembly-83@lists.ticalc.org <assembly-83@lists.ticalc.org>
>>Date: Thursday, October 22, 1998 1:48 PM
>>Subject: A83: SpRiTes ?
>
>
>>>
>>>Hi !! :)
>>>That's me again (the french guy...).I'm still learning ASM
>>>and problems come to me (why???):
>>>-sprites' problems
>>>When my sprite is moving (right/left/up/down, whatever),
>>>it flash..?
>>>How can I avoid that ?
>>>
>>>THX ;)
>>>
>>>yhean
>>>
>>>(thanks to Linus and Alan C Johnson for their answers about Zasmload)
>>>
>>>
>>>
>>>Get your FREE E-mail at http://mailcity.lycos.com
>>>Get your PERSONALIZED START PAGE at http://personal.lycos.com
>
>