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Old 27 February 2021, 22:41   #241
skan
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Quote:
Originally Posted by kremiso View Post
Another game i would have liked to see in AGA vest is surely Jim Power -...
...
it received also a decent and colorful ms-dos port at the time :
longplay PC
[ Show youtube player ]

in reality i like almost all the ports of this game (and the original of course), so i would like to see a sort of 'back to home' at some point
Yeah, I also wonder if the DOS version would run on a 1200 (maybe with a proper parallax fx too )

Another DOS enhanced game I'd like to see on a 1200 is Turrican 2, pretty colorful and detailed IMHO.
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Old 27 February 2021, 22:59   #242
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Here they mention (in French) a burst mode for the blitter, is that real or they're just mistaking $dff1fe & the copper burst mode ($dff1fc) ?

http://obligement.free.fr/articles/b...ode_rafale.php
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Old 27 February 2021, 23:17   #243
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That article is wrong. There is no Blitter burst mode. Then again, there's no Copper burst mode either
Edit: to be clear, you can set the AGA chipset into an increased fetch mode, but that only increases the speed of the reading of bitplane data by Lisa for display. This will impact the Copper and Blitter, but not in the way the article suggests.
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Old 27 February 2021, 23:22   #244
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Quote:
Originally Posted by hitchhikr View Post
Here they mention (in French) a burst mode for the blitter, is that real or they're just mistaking $dff1fe & the copper burst mode ($dff1fc) ?

http://obligement.free.fr/articles/b...ode_rafale.php
Yes, it works! But is a bit complex to activate.
The following values must be written in a precise timeline in $dff1fe:
Code:
	move.w	#$4255,$dff1fe
	move.w	#$4c4c,$dff1fe
	move.w	#$5348,$dff1fe
	move.w	#$4954,$dff1fe
Then you can enjoy the ultra-secret undocumented 4X blitter burst mode
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Old 27 February 2021, 23:27   #245
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Quote:
Originally Posted by ross View Post
Yes, it works! But is a bit complex to activate.
The following values must be written in a precise timeline in $dff1fe:
Code:
    move.w    #$4255,$dff1fe
    move.w    #$4c4c,$dff1fe
    move.w    #$5348,$dff1fe
    move.w    #$4954,$dff1fe
Then you can enjoy the ultra-secret undocumented 4X blitter burst mode
Don't be afraid if you can smell the result. That's normal
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Old 27 February 2021, 23:38   #246
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I thought so (even if that's apparently extracted from "Amiga News" which was a quite serious magazine).
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Old 28 February 2021, 14:04   #247
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Quote:
Originally Posted by hitchhikr View Post
Here they mention (in French) a burst mode for the blitter, is that real or they're just mistaking $dff1fe & the copper burst mode ($dff1fc) ?

http://obligement.free.fr/articles/b...ode_rafale.php
Quote:
Originally Posted by ross View Post
Yes, it works! But is a bit complex to activate.
The following values must be written in a precise timeline in $dff1fe:
Code:
	move.w	#$4255,$dff1fe
	move.w	#$4c4c,$dff1fe
	move.w	#$5348,$dff1fe
	move.w	#$4954,$dff1fe
Then you can enjoy the ultra-secret undocumented 4X blitter burst mode
it is an unexplored feature, or maybe no real benefit could be gained using it?
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Old 01 March 2021, 10:23   #248
dlfrsilver
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Quote:
Originally Posted by Tsak View Post
Street Fighter Alpha 2 and Street fighter Zero 2 released for the SNES did use the S-DD1 chip. So this might be the source for this mix up.
Very Possibly. Without the S-DD1, SFA2 SFZ2 are no go on SNES.
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Old 01 March 2021, 10:54   #249
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Quote:
Originally Posted by kremiso View Post
it is an unexplored feature, or maybe no real benefit could be gained using it?
Ross was joking, there is no unexplored feature (so also no benefit as it doesn't exist ).
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Old 01 March 2021, 13:05   #250
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Originally Posted by roondar View Post
Ross was joking, there is no unexplored feature (so also no benefit as it doesn't exist ).
No - this is BULLSHIT.
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Old 01 March 2021, 13:13   #251
Steril707
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Quote:
Originally Posted by ross View Post
Yes, it works! But is a bit complex to activate.
The following values must be written in a precise timeline in $dff1fe:
Code:
	move.w	#$4255,$dff1fe
	move.w	#$4c4c,$dff1fe
	move.w	#$5348,$dff1fe
	move.w	#$4954,$dff1fe
Then you can enjoy the ultra-secret undocumented 4X blitter burst mode
Naughty Dog will hate reading this, but I have a working prototype of Uncharted 4 running on an A500 using this trick.
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Old 01 March 2021, 13:27   #252
kremiso
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Quote:
Originally Posted by roondar View Post
Ross was joking, there is no unexplored feature (so also no benefit as it doesn't exist ).
got the joke, thanks
but now i'm curious what those Ross 4 code lines exactly do, as a non programmer

maybe the Guru Meditation final fix?
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Old 01 March 2021, 13:35   #253
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Ahh, would've been nice though - undocumented 4x Blitter speed would be the scoop of the century :P

Quote:
Originally Posted by kremiso View Post
got the joke, thanks
but now i'm curious what those Ross 4 code lines exactly do, as a non programmer

maybe the Guru Meditation final fix?
The write the word BULLSHIT into the non-existent register. So err, nothing
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Old 01 March 2021, 14:58   #254
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Here they also mention this features
https://ada.untergrund.net/?p=boardthread&id=1022

Last edited by sokolovic; 01 March 2021 at 15:10.
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Old 01 March 2021, 15:10   #255
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Originally Posted by sokolovic View Post
Here they also mention that features
https://ada.untergrund.net/?p=boardthread&id=1022
It's a bit confusing perhaps, but they're talking about display fetch modes, not a burst mode for the Blitter. AGA does have a display fetch 'burst mode', but like said it doesn't have one for the Blitter.
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Old 01 March 2021, 15:10   #256
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Blitter Is faster cos you have more dma cycles to use
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Old 01 March 2021, 15:51   #257
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Quote:
Originally Posted by roondar View Post
It's a bit confusing perhaps, but they're talking about display fetch modes, not a burst mode for the Blitter. AGA does have a display fetch 'burst mode', but like said it doesn't have one for the Blitter.

I'm really not a specialist so indeed that's a bit confusing, especially when they write in this link :

Quote:
As my demo use any of (what I call) X1,X2 or X4 burst mode,all my aga copperlist start with "fmode,value", simply because everything can be changed each frame.
(actually my fmode values are always or'ed with $00c0 because these bits are the 64 pixel sprite mode, and it doesn't affect the following.)

Why using fmode ? Because with X4 the blitter is 2 times faster, quite faster in X2, and I suspect CPU itself to be faster as far as Chip ram is concerned.

That said, what are the advantadges of the AGA display fetch mode burst mode you mentionned ?
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Old 01 March 2021, 15:59   #258
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Ok, here's the short form of what's going on:
  1. All Amiga's (from A1000 to A4000) have essentially the same Blitter
  2. The Blitter has the same speed on all Amiga's.
  3. What changes between OCS/ECS/The A3000 and AGA is only how much time the Blitter has to spend waiting on other DMA sources (mostly the display)
  4. AGA's higher fetch modes don't speed up the Blitter, they give the Blitter a larger percentage of useful cycles
  5. The result of this is that the Blitter can appear to be faster (quite a bit in some cases), but in reality both an A1000 and an A4000 will run the Blitter at the same speed* if the display etc are turned off.
*) Just looking at the Blitter here, not at the faster CPU being able to set up the Blitter faster.
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Old 01 March 2021, 23:09   #259
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Sega would definitely have called this 'blast processing' and Sony, 'the emotion engine'
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Old 01 March 2021, 23:14   #260
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Originally Posted by khph_re View Post
Sega would definitely have called this 'blast processing' and Sony, 'the emotion engine'
Haha, I remember the hype for the emotion engine. Genius PR.
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