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From: markv@kuhub.cc.ukans.edu
Newsgroups: comp.sys.amiga.programmer
Subject: Re: 1.3/2.0 Question
Message-ID: <28631.27bd98b0@kuhub.cc.ukans.edu>
Date: 17 Feb 91 02:40:16 GMT
References: <1991Feb15.193645.1315@mintaka.lcs.mit.edu> <19028@cbmvax.commodore.com>
Organization: University of Kansas Academic Computing Services
Lines: 33

>>If the animation routines in GfxLib pull down the system that much they
>>are not very usuable (except simple-sprites). Banging on the hardware
>>starts to look real good.
> 
> They do use a lot of horsepower.  They're pretty general-purpose.  There
> are lots of code-it-yourself alternatives that don't involve banging
> on the hardware but give you better performance with a loss of generality.
> 
>>  I don't understand how a routine to move 1 or 2 bobs across the screen
>>is going to eat up almost 100% of the CPU (7mhz). After all, bobs (blitter)
>>are rendered in parallel.
> 
> There still is only one blitter, and there is set-up work and so on.

Agreed.  Also, do you have any FAST ram?  Dont forget that the blitter
is async, but only one guy can access RAM at a time.  I know from very
careful work, expirimentation, simple math, etc. there is just barely
enough RAM cycles for the blitter to do a 2 channel operation (like
copy/move or mask) per frame on 2 640*200 bitplanes when the display is the
same.   If you have no fast RAM and the CPU needs to do much, then you
are really out of luck.  Before people complain about how slow the
Blitter is these days, it still sure beats nothing at all (which is still
the case with 99.9% of non-Amiga desktop micros today).

-- 
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