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Demos Amiga Demoscene Archive Forum / Coding / AGA advantages over OCS from a demo coder perspective

 

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RetroCoder
Member
#1 - Posted: 18 Apr 2007 12:32
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Hi,
I only coded one game on A1200 and that was a cheap port of the A500 version so didn't really use any special features. That was long ago and my memory is shot as to what the advantages of AGA were other than better CPU and the introduction of a cache(if memory serves me correct). However, I'm interested in knowing what advantages demo coders have with AGA. Looking at the best ever demos on this site clearly shows AGA as having way nicer effects than OCS - texture mapping, more complex objects etc. Is this all a throwback from the faster CPU allowing quicker C2P or is there something nice about the blitter or display modes?

Second question, regarding c2p on an a500. Atari seems to win with its interleaved format/movep trick. Have any tricks been found for the A500 - can the blitter be utilized in any way?

Thanks guys - any info appreciated...
Toffeeman
Member
#2 - Posted: 18 Apr 2007 12:45
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Yeah lots of the texture mapping C2P effects are mainly because of the faster processor rather than AGA. AGA does offer

- 8 bitplanes
- 24 bit palette.
- 64 pixel wide sprites
- Super hi-res scrolling
- HAM8
- Display hardware is basically 4x faster

The blitter and copper are exactly the same but can access 2 meg chip ram. Here is a link to AGA coding:-

http://www.mways.co.uk/amiga/howtocode/text/aga.ph p

Second question check this thread on here:-

http://ada.untergrund.net/forum/index.php?action=v thread&forum=4&topic=217
RetroCoder
Member
#3 - Posted: 18 Apr 2007 14:46
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Thanks Toffeeman. Do you know which are the better A500 only demos that use c2p style effects?
Toffeeman
Member
#4 - Posted: 18 Apr 2007 16:34
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First kind of effect I know of is the "Amiga Rules" Rotozoom in World Of Commodore by Sanity. Then they progressed to 4 bitplanes in Arte. Then check out there AGA demo Roots which uses this effect again. I don't think during the day 87 to 95 that to many people knew how todo this effect. I'm sure there are more examples though.

The coder Sp has been doing this effect recentley and theres a great thread on it here:-

http://www.pouet.net/topic.php?which=3838&page=1&x =11&y=10
sp_
Member
#5 - Posted: 28 Jun 2007 15:26
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retrocoder: regarding fast chunky to planar on amiga500 by using the blitter. look at this thread.

http://ada.untergrund.net/forum/index.php?action=v thread&forum=4&topic=217

I have a txturemapproutine running in good framerate on the vanilla a500 by using selfmodified code in scrambled chunkybuffer with blitter doing the c2p. Planned to release something for assembly oldschool compo, but I dont have tome to code at the moment,

 

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A.D.A. Amiga Demoscene Archive, Version 3.0