Is Amiga Emulation better than the real thing?

[bloodline]

amigaksi wrote:
>>If you had the Amiga VBI perfectly synched to PC VBI, than you would be resynching every 1/60 second, but still what happens in between those refreshes will be out of sync given different cycles times. Usually, PC VBI isn't the same rate as Amiga VBI and PC emulation has the latency to begin with and may also be out of phase.

>I'm not even sure anything you just said made any sense... But hey ho... I can easily run my gfx cards at 60hz, then use the gfx card's VBI to sync the emulation's virtual VBI to the real world... That would give me a nice NTSC emulation. But if I want a 50hz interrupt for PAL emulation, then I would run the gfx card at 100hz and sync the emulation every two real frames.

NTSC rate isn't exactly 60Hz, it's more like 60/1.001.  And anyway, your video card isn't doing 262.5 scanlines per field nor is a user response showing up in same time as on emulator given the buffer approach.  

True actually, NTSC is 59.98 or something and that is very slightly too slow but I know the human eye can't see the difference between the two rates... And I personally run my stuff in PAL anyway and 50hz is possible on modern cards by halving the 100hz rate. As for your dislike of the "buffer approach", I suggest you throw away all your amiga games as they all use double buffering... Have you ever writen a game on an Amiga?  

>Given the fact that re granularity of this system is based on the frame rate, since a human being's senses are being refreshed at 50/60hz on both the real and emulated Amiga (and the fact that a PC can do all work that a real Amiga can normally do in 25ms, in ~1ms so it spends most of it's time just waiting for the sync), the emulation and real Amiga will be in the same state WRT the user at all times. This really is elementary stuff...

Not true so not elementary.  For example, if Amiga moves a screen full of sprites in a few microseconds, the PC will take much longer since most video cards can't update their display in a few microseconds so emulators will hope that time will be made up for by other things.  Our senses aren't being refreshed at 60Hz on real Amiga but higher frequency.  Only display is around 50/60Hz.

A modern gfx chip can redraw an entire screen, perform thausands of blitter operations and render a 3D scene... At many times the resolution of the Amiga in far less time than it takes for an Amiga to update the sprite registers...

[Seiya]

Varthall wrote:
For 68k Amigas it might be true, not for PPC ones though since no emulator for such machines exists.

Varthall

PowerPC emulator for windws there is, and they are able to run very well macOS PPC as far as MacOS9.04.

The problem, is that there aren't amiga ppc emulator.

OS4 and MoprhOS on Virtual Machine or in a WinUAE with PPc emulation, could stop further hardware developments

[ChaosLord]

Bloodline wrote:

I suggest you throw away all your amiga games as they all use double buffering... Have you ever writen a game on an Amiga?

I have, and so have some of my friends.  None of them use double-buffering.  AFAICT double-buffering is only really useful when displaying an FMV movie.  It is often a mistake to double-buffer a whole game on the Amiga.  The Amiga has real-time beam position knowledge with approximately 1/21000000th second resolution (if you want the exact number then consult your HRM).

[shoggoth]

ChaosLord wrote:
I have, and so have some of my friends.  None of them use double-buffering.  AFAICT double-buffering is only really useful when displaying an FMV movie.  It is often a mistake to double-buffer a whole game on the Amiga.  The Amiga has real-time beam position knowledge with approximately 1/21000000th second resolution (if you want the exact number then consult your HRM).

ChaosLord - you're probably thinking of 2d games. Generally 3D games are double-buffered.

[ChaosLord]

Yes I was thinking of 2D games.  Most Amiga games are 2D.

I would assume that most 3D games and some 2D games use double buffering.

[bloodline]

ChaosLord wrote:
Bloodline wrote:

I suggest you throw away all your amiga games as they all use double buffering... Have you ever writen a game on an Amiga?

I have, and so have some of my friends.  None of them use double-buffering.  AFAICT double-buffering is only really useful when displaying an FMV movie.  It is often a mistake to double-buffer a whole game on the Amiga.  The Amiga has real-time beam position knowledge with approximately 1/21000000th second resolution (if you want the exact number then consult your HRM).

Unless you are only using sprite and static sceens (or hardware scrolled screens), no double buffering will look like crap... All blitter ops will look nasty... The blitter was the best thing in the Amiga chipset... IMO

[ChaosLord]

no double buffering will look like crap... All blitter ops will look nasty

Wrong.  It all depends on what you are blitting and if you are making use of the Amiga chipset's awesome features (Jay Miner rulez 4eva) and how you have written your code.  Some games require double-buffering and some do not.

[bloodline]

ChaosLord wrote:

no double buffering will look like crap... All blitter ops will look nasty

Wrong.  It all depends on what you are blitting and if you are making use of the Amiga chipset's awesome features (Jay Miner rulez 4eva) and how you have written your code.  Some games require double-buffering and some do not.

I'm not going to be drawn into a debate as to the "correct" usage of the Amiga chipset, suffice to say if you want make a game that looks really good you need to use the blitter quite extensively, and the slowness of the blitter will need to be smoothed out with double buffering, which I might add the Amiga chipset was rather well suited to.

On topic, I could easily set up an Emulation that no one here would be able to tell from a real Amiga... I have just such a WinUAE set up on my MacBook Pro for running Shadow of the Beast II...

[amigaksi]

>by shoggoth on 2009/1/27 6:23:15

>>"to try to equal of surpass; imitate so as to excel: to emulate the success of great writers." - Page 258, Dictionary by Harcourt Brace Jovanovich, Inc.

>Hmm.... I wonder which definition that applies to this discussion.

Whichever a person understands when he reads a statement "PC can emulate Amiga with cycle-accuracy."  I understood it as what I quoted.  If it's just an attempt, it's trivial then.

>You'd have to be a complete moron not to understand that it does, especcially when there is an additional definition for the word when used in the context of *computers*.

Your insults don't help nor do your straw-man arguments.  Words are defined by their context.  People I know threw away their Amigas because of the way they understood the misleading remarks.

>http://en.wikipedia.org/wiki/Emulation_(observational_learning)

I have also read many articles on wikipedia and other internet sources that are wrong.  I rather trust a published dictionary.

>>I don't know which posts you are referring to. All my posts are accurate given the definition above. If I take your definition, then it gets silly-- Atari 800 can emulate a Pentium IV, Quad core given enough time.

>That's taken out of context. In theory the statement is true, given enough time and memory - that was the point of it. In practice it's completely retarded. Just like some posters in this forum.

Your insults don't help nor do your straw-man arguments.  If you can't deal with the facts, that's your problem.  I already told you I don't accept your definition.  Atari CANNOT emulate a Pentium IV, Quad core-- there's no way to execute two instructions simultaneously amongst other things.

[amigaksi]

>by ChaosLord on 2009/1/27 8:43:29

>Yes I was thinking of 2D games. Most Amiga games are 2D.

>I would assume that most 3D games and some 2D games use double buffering.
 
There are problems with double buffering as well...  And if the user interacts, then the latency effect won't get buffered whereas the video/audio is still buffered.

[amigaksi]

>A modern gfx chip can redraw an entire screen, perform thausands of blitter operations and render a 3D scene... At many times the resolution of the Amiga in far less time than it takes for an Amiga to update the sprite registers...

You need to calculate this out and you'll see that modern graphics cards cannot redraw an entire screen (repaint).  If they have built-in similar hardware sprite-type stuff, they can probably keep up.

[amigaksi]

>by shoggoth on 2009/1/27 6:39:12

>>You are being vague. I have stuck to my position for many years now although in the process HPET got introduced and Vista came out.

>No. I entered this discussion because:
>A: You make claims about how emulators work.
>B: Those claims are completely wrong.

You haven't shown any of my claims to be wrong.  You just have a different definition of cycle-accuracy and emulation.  All of my statements are proven.

>I've got a question for you, Amigaski:
>A: You know how emulators work internally, and therefore your statements about emulators are true.
>B: You don't know how emulators work internally, but you do know for a fact that your statements are true anyway.

>Which one is it, Amigaski? A or B?

I already answered this.  It's C-- I know how the PC works and Amiga works so I know whether some Amiga function can be emulated on the PC.  It's called deductive logic-- not straw man argument or insult like you use.  Here's a simpler example, I know for a fact that Gameport joystick on PC takes 1 ms to read using port 201h (directly read port).  I know Amiga joystick read takes, a few microseconds.  Thus, you cannot emulate an Amiga joystick on PC using PC joystick.  It'll never EQUAL OR EXCEL it.

Same claims I made using timers with 1.19Mhz timer vs. 7.16Mhz cycle accuracy and other claims.

[bloodline]

amigaksi wrote:
>A modern gfx chip can redraw an entire screen, perform thausands of blitter operations and render a 3D scene... At many times the resolution of the Amiga in far less time than it takes for an Amiga to update the sprite registers...

You need to calculate this out and you'll see that modern graphics cards cannot redraw an entire screen (repaint).  If they have built-in similar hardware sprite-type stuff, they can probably keep up.

Sorry amigaski, I hate to use the phrase "you're wrong", but you really are... The weakest gfx card I own is able to push 3.4Gigabytes per second... The amiga struggles to keep up with 2megabytes per second and this is using AGA!!! The Amiga is Very Old technology, it is very slow and lacks the resolution and colour depth of modern hardware... It can't compare!

[ChaosLord]

Sorry bloodline, I hate to use the phrase "you're wrong", but you really are... The weakest Amiga I own is able to push a lot more than 2 megabytes per second.

[bloodline]

ChaosLord wrote:
Sorry bloodline, I hate to use the phrase "you're wrong", but you really are... The weakest Amiga I own is able to push a lot more than 2 megabytes per second.

Ok, but even if we include your magical blitter engine that can push the Amiga's blitter beyond even its theoretical maximum transfer rate, you can't deny that a modern gfx chip can outperform the Amiga by several orders of magnitude!!! Honestly there is nothing the Amiga can do that I can't do faster with more colours and at a greater resolution on a modern chip... That is just simple physics! You can even prove it yourself using SDL!!!

[dammy]

Sorry bloodline, I hate to use the phrase "you're wrong", but you really are... The weakest Amiga I own is able to push a lot more than 2 megabytes per second.

I'll bite, how many MBPS in what slowest Amiga?

Dammy