Amiga emulators: is it worth it?

[AmiKit]

@DiskDoctor

Maybe the performance of the user? With AmiKit you can eg. unpack archives with simple drag&drop. This saves much time compared to the bare system which doesn't even have any unpacker program installed...

[DiskDoctor]

AmiKit wrote:
@DiskDoctor

Maybe the performance of the user? With AmiKit you can eg. unpack archives with simple drag&drop. This saves much time compared to the bare system which doesn't even have any unpacker program installed...

Well as far as I know a solution's performance one might think of as the level of usability, as compared to the level designed/deserved or some other solutions' level.

So performance is measured by a performance of the user actually.  To the user.

This is all about making things easier; the main reason many people do not use Linuxes is that one needs significant effort (or knowledge or time) to get most stuff work on it, since Win and Mac versions seem causing no problems on installation and are always ready to use.

Users are not necessarily also computer geeks.
Or sometimes they simply do not want to be.

So, still, I claim some alternative distribution working fine without any extra set-up effort (RTFM? No thanks, I'll just step into another store) performs better, from any application's proper perspective - the user perspective.

[amigaksi]

>Experimental results? Lol, you still don't get it, do you? It is the subjective human perceiving that counts here. Not the small difference in exact numbers, voltage or whatever.

Okay, if you can live with the inaccuracies of those softwares you are using the emulator for, great.  But it does not take away from the FACTs that some software won't work given those inaccuracies and other humans can perceive differences where you may not.  Some people I know think the lossy MP3 is same as 16-bit lossless linear audio CDs.  They may live with it, but objectively studied-- you can compare the original digitized wave file to the audio CD and MP3 file and show the distortions caused by MP3.

>Look, I understand that from objective point of view the emulated Amiga on PC hardware is not Amiga. But my favourite games behave just like they behaved on my real Amiga. At least my impression is the same. So from MY point of view it IS Amiga. I really don't care about the PC HW that is under the desk, I don't care about cycle-exact issue or whatever. I don't need to do experimental HW research in order to increase my subjective impression of the game, etc. That's it.

You are studying a small sample only.  I can write software where even YOU will notice a difference.

[amigaksi]

>by AmiKit on 2009/1/20 5:29:32

>@spirantho

>Are we still talking about A500 games?
>Even WHDLoad on a real machine (A1200 and better) can be considered as emulation when running A500 games - in strict point of view.

But there's a big difference.  AGA is a superset of the OCS hardware (and backward compatible).  You can write software for OCS that works fine on AGA w/o modifications.  It's just that some software used the CPU for timing or called OS routines at absolute locations or something like that which you need adjust to make them compatible.

>If those things are imperceptible, what makes the difference in your feelings? Just the knowledge that it is the emulation? If so, that is exactly what Turing test eliminated.

>--Jan

You can tell certain differences if you are really addicted to a game and know its nuances rather than if you just played it once or twice or just saw it.  Audio and Video is not the only thing of our experience, subtle timings also is in our experience which you seem to be throwing under the "subjective" catagory.  And even for a buffered 60Hz display, if you don't properly sync up the frames to the same VBlanking used by Amiga, you can notice the 1/60 difference.  And for audio, it's much higher frequency that one can notice.

[AmiKit]

@amigaksi

...humans can perceive differences where you may not.

Exactly...   wait a sec, does it mean I am not a human? ;-) Just kidding.

Some people I know think the lossy MP3 is same as 16-bit lossless linear audio CDs.

You mix the knowledge and the experience. If they cannot differentiate between lossy MP3 and WAV, in their world lossy MP3 is OK. No need for "objective" studies.

You are studying a small sample only.

Yep, but it doesn't mean it's bad. Seems we're getting to the core finally. While you're talking about nomothetic approach I am talking about ipsative or individual approach. Now the question is what approach is more suitable when talking about emulated games. I think that with regards to the impression of the game the INDIVIDUAL EXPERIENCE is more important than subtle differences in video, sound or timing (if there are any, of course).

You can tell certain differences if you are really addicted to a game and know its nuances rather than if you just played it once or twice or just saw it. Audio and Video is not the only thing of our experience, subtle timings also is in our experience which you seem to be throwing under the "subjective" catagory. And even for a buffered 60Hz display, if you don't properly sync up the frames to the same VBlanking used by Amiga, you can notice the 1/60 difference. And for audio, it's much higher frequency that one can notice.

If there really is any 1/60 difference then the fact whether the human can notice or not depends on the intensity of the original value. This is called Weber-Fechner law. Needles to say that such a 1/60 difference, even though noticed, won't affect your game experience at all. It objectively affects your measurement device only.

I can write software where even YOU will notice a difference.

That would be interesting.

[amigaksi]

>by AmiKit on 2009/1/21 5:56:17

>>@amigaksi
>>...humans can perceive differences where you may not.

>Exactly... wait a sec, does it mean I am not a human?  Just kidding.

There was the word "other" before humans.  People addicted to a game (or application) get used to the audio/video/timing so what they did not perceive initially they perceive later.  And with MP3, it's similar-- if you show them the distortions by selecting the appropriate parts of the wave and original wave and playing them one after another, they can notice the difference.  So it's not a constant.

>>Some people I know think the lossy MP3 is same as 16-bit lossless linear audio CDs.

>You mix the knowledge and the experience. If they cannot differentiate between lossy MP3 and WAV, in their world lossy MP3 is OK. No need for "objective" studies.

Yes, there is.  When people create a product they are targetting the general populace with various interests/levels of perception.  You have to take an objective approach although different people may have different levels of requirements.

>>You are studying a small sample only.

>Yep, but it doesn't mean it's bad. Seems we're getting to the core finally. While you're talking about nomothetic approach I am talking about ipsative or individual approach. Now the question is what approach is more suitable when talking about emulated games. I think that with regards to the impression of the game the INDIVIDUAL EXPERIENCE is more important than subtle differences in video, sound or timing (if there are any, of course).

There is a difference so let's not put that into doubt as we only need to show one example to prove they are different.  And we already know the latency is purposely there.  What you need to do is change the "the" in front of "the INDIVIDUAL EXPERIENCE" to "MY".  "The" would imply an objective approach.

>If there really is any 1/60 difference then the fact whether the human can notice or not depends on the intensity of the original value. This is called Weber-Fechner law. Needles to say that such a 1/60 difference, even though noticed, won't affect your game experience at all. It objectively affects your measurement device only.

Sorry, it does not depend on any "intensity".  It's not so vague.  Just move a screen large object a few pixels every 1/60 of a second.  So if you are in 320*240 mode, say you can move object 320 pixels in 2 seconds.  Well, if your emulator does not know when that position changes, 1 frame will show part of the object moving and another frame will show the rest of the object.

>>I can write software where even YOU will notice a difference.

>That would be interesting.
 
Not "would be".  It is already existing.

[amigaksi]

>by shoggoth on 2009/1/20 11:33:18

>>amigaksi wrote:
>>If you go by PC standard hardware, it is impossible to >>do the cycle-exact emulation of the Amiga.

>I'd like to see you explain that statement. Emulation granularity is *not* dictated by hardware capabilities such as timers, sprites, multi-channel audio chips. Generally that's not how you solve these things, at least not in any of the emulators I've worked on.

It's good to have conversations and learn things but when you start insulting and poking fun at the other party, that "learning" experience goes away and it's more to do with biased emotional sentiments.

Accurate emulation depends on hardware capabilities.  I'll explain it further if I feel like it.

[shoggoth]

amigaksi wrote:
It's good to have conversations and learn things but when you start insulting and poking fun at the other party, that "learning" experience goes away and it's more to do with biased emotional sentiments.

No, you're making false statements, and you don't appreciate when people correct them.

If I do have a bias, it favours amiga and other machines of that era. I appreciate the complexity and capabilities of these machines, but I don't let that blind me or prevent me from accepting technology today.

I claim that you have decided that these machines cannot be emulated accurately, based on wrongful assumptions about how emulators work internally. For that reason, I've explained how they work. If you don't want to accept that, you're simply rejecting reality in favour of your wrongful assumptions.

Accurate emulation depends on hardware capabilities.  I'll explain it further if I feel like it.

No, it does not. You need enough CPU power, that's it. You don't need high resolution timers or any of the other stuff you've stated.

Marat Fayzullin has written a simple yet very informative tutorial about writing computer emulators. You can find it here: http://fms.komkon.org/EMUL8/HOWTO.html

Marat is well known for his work. If you look at his source code, or the source code of 95% of the emulators on the net, you'll find that they do *not* rely on timers nor special hardware capabilities to ensure cycle accuracy. They do so by interleaving the code for each emulated subsystem. In the case timers are used, it's generally to throttle emulation so that it does not run too fast, or to skip frames to maintain speed.

[fishy_fiz]

@DiskDoctor

I see you mention Amiga OS4.x in a few of your posts in this topic. I appologise if youre aware of the following, but just incase youre not there are a few things to be aware of.  Firstly OS4.x wont run on any current emulator. Id be surprised if this didnt change in time, but I wouldnt hold my breath for it. Also in regards to the emulator built into OS4.x, it will only work for system friendly software. Ninety plus percent of old classic games simply wont work and will require running E-UAE ontop of OS4.x to get them working, which unfortunately isnt the best experience. Lack of both hardware power and jit cpu emulation makes even ocs/ecs software very sluggish on a Sam440 system (to a point of being next to useless in my opinion). Some of the A1 systems fare a little better, and will let you play a good portion of ocs/ecs games at a reasonable speed if you set it to skip a frame or 2 (and some stuff without frameskip). Very few AGA games however are usable on any of the current PPC/OS4.x systems ("usable" however is probably a little bit of personal taste, and some people may be happy with disabling sound and jerky movement). 68k software that doesnt directly hit custom chipset (mostly apps, but some of the more recent 68k amiga games too) will generally run quite nicely though, even on a Sam440.

[amigaksi]

>by shoggoth on 2009/1/22 8:11:28

>No, you're making false statements, and you don't appreciate when people correct them.

That's a false statement.  Claiming that cycle-accurate should mean 1/7.16Mhz timing accuracy on OCS Amiga is false right?  Perhaps, your term is misleading others-- care to think of it that way?

>If I do have a bias, it favours amiga and other machines of that era. I appreciate the complexity and capabilities of these machines, but I don't let that blind me or prevent me from accepting technology today.

I never said technology today should not be accepted.

>I claim that you have decided that these machines cannot be emulated accurately, based on wrongful assumptions about how emulators work internally. For that reason, I've explained how they work. If you don't want to accept that, you're simply rejecting reality in favour of your wrongful assumptions.

Based on facts about hardware of target platform and source platform (Amiga), I made my statements-- I can verify all my statements.  I have nothing to gain by speculating something imaginary nor are you stating what those "wrongful assumptions" are.

>>Accurate emulation depends on hardware capabilities. I'll explain it further if I feel like it.

>No, it does not.

Yes, it does.  See below.

>You need enough CPU power, that's it. You don't need high resolution timers or any of the other stuff you've stated.

Regardless, of how fast your CPU is, it won't make your beep speaker (1-bit resolution) do 4-channel 16-bit 44Khz audio.  Regardless if your CPU is Pentium IV at 4Ghz, it won't improve your timers.  And you can't time things equally or better with 1.19Mhz timer vs. a 3.57Mhz timer-- just seems to be violating some laws.

>Marat Fayzullin has written a simple yet very informative tutorial about writing computer emulators. You can find it here: http://fms.komkon.org/EMUL8/HOWTO.html

He is claiming any computer can be emulated because he defines "emulate" as an ATTEMPT to imitate the target machine.  That means, you should also accept: Atari ST can emulate Amiga, Atari 800 can emulate Pentium IV dual core, Apple I can emulate the MAC II, etc.  

[persia]

A Pentium 4 is yesterday's technology, Core2 and Quad Core Xeons are the processors of today.  I've qot a pair of Quad Core Xeons in my machine...

[bloodline]

amigaksi wrote:

Regardless, of how fast your CPU is, it won't make your beep speaker (1-bit resolution) do 4-channel 16-bit 44Khz audio.  Regardless if your CPU is Pentium IV at 4Ghz, it won't improve your timers.  And you can't time things equally or better with 1.19Mhz timer vs. a 3.57Mhz timer-- just seems to be violating some laws.

On my nice new 2.8Ghz Core2Duo, UAE uses ~12% of my CPU when emulating an A500 using the most accurate, most compatible settings... the video and audio are perfect...

Put it another way, it doesn't matter about timers, the Emulator is able to complete all required operations and then spend 88% of it's time just waiting to run the next cycle...

No matter how you try and spin it, a 2.8Ghz CPU can easily accommodate the 28Mhz system of the Amiga.

[shoggoth]

by amigaksi on 2009/1/22 12:25:08
That's a false statement. Claiming that cycle-accurate should mean 1/7.16Mhz timing accuracy on OCS Amiga is false right?

No, cycle accuracy at 1/7.Mhz granularity is perfectly possible without using timers. Get those timers out of your head.

Based on facts about hardware of target platform and source platform (Amiga)

... based on facts about hardware - but not based on how emulators actually work. You've *assumed* that they work in a certain way using timers - which they generally don't (because it would be completely retarded to do it that way).

Regardless, of how fast your CPU is, it won't make your beep speaker (1-bit resolution) do 4-channel 16-bit 44Khz audio.

Now you're just being silly. Of course you need a soundcard to get proper sound. That wasn't the point - we were discussing emulation accuracy.

Regardless if your CPU is Pentium IV at 4Ghz, it won't improve your timers. And you can't time things equally or better with 1.19Mhz timer vs. a 3.57Mhz timer-- just seems to be violating some laws.

Drop timers. You don't use timers to achieve accurate emulation. That's *in* your *head*. You've chosen to compare this aspect of computers because it suits your ideas, obviously.

He is claiming any computer can be emulated because he defines "emulate" as an ATTEMPT to imitate the target machine. That means, you should also accept: Atari ST can emulate Amiga, Atari 800 can emulate Pentium IV dual core, Apple I can emulate the MAC II, etc.

LOL! So by this you claim that Marat Fayzullin has no idea what he's talking about? :-D Do you know who this guy is?

"... as an ATTEMPT to imitate" - well that's *exactly* what emulation is. And emulation accuracy is defined by compatibility and perceived user experience. Both which can be realized on any PC today. If you ignore the latter, even a ZX81 can accurately emulate a modern quad core x86 class machine, given enough time and memory.

I'll try to refrain from further comments now, since there is no point in discussing a topic such as this one with you. You're either incredibly ignorant or trolling, or both.

[DiskDoctor]

 
 @ shoggoth
&@ amigaksi

Guys guys.

Theoretically, given enough speed, say some 10^[original processor speed] x each unit (CPU, graphic etc) one might emulate everything.  Hardware or software, it's a manner of coding efficiency, nothing else (except core I/O).

Old Amigas were excellences, though nothing divine.  Sure it is theoretically possible to re-create this.  But I do not think it is doable on the current PC stuff especially with all WinLinMac stars as middleware...  Nowadays, like software (OS), like hardware.

I was always a critic of this all PC/Mac (maybe less Mac) TB/PHz World of Waste and Pathos.  Just compare the figures with efficiency.  20 years ago I would have said... ill...  That's why I will NEVER leave Amiga.  

This post's purpose was to put the point "UAE works everywhere" in question as I can sense it.  The issue is rather... what if not? why? what then?

I'm thinking that good idea would be mixing Linux with UAE so that it makes a standalone bootable Amiga-like environment, DEDICATED to the PC hardware.  Is it so hard to shed all unnecessary (95%) linux tasks and reinforce the rest with core Amiga emulation functions??  There are so many Linuxes, why not Aminux for a change?

What do you think?

[ferrellsl]

What you're talking about has already been done.  It's called Amithlon.  Works very well on older hardware.

[DiskDoctor]

ferrellsl wrote:
What you're talking about has already been done.  It's called Amithlon.  Works very well on older hardware.

But isn't it like discontinued now?  If I can get it, working, I'm ready do pay much.