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Old 01 June 2016, 16:02   #281
Lord Aga
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That is correct. But since we haven't used the word emulation so far when we spoke of the other CPUs in the family, why start now ?
Either everything (but the original IC) is emulation, or nothing (other MC CPUs, FPGAs...) is.
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Old 01 June 2016, 16:11   #282
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Look, I'd had a lovely supper, and all I said to my wife was that piece of halibut was good enough for Jehovah!

Whatever you want to call it, call it that . I honestly couldn't care less. What I would care about is someone with the skills to say, "ah yes, great, let's see how we can do that then..." . I don't have 'em.

This is an interesting approach - https://github.com/mntmn/amiga2000-gfxcard ...
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Old 01 June 2016, 16:38   #283
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A 68020 is a 68020. It is backwards compatible with the 68000, albeit not completely.
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Old 01 June 2016, 16:51   #284
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"It still isn't a 68000."
So it's an emulator ?
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Old 01 June 2016, 16:52   #285
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Quote:
Originally Posted by Lord Aga View Post
So it's an emulator ?
Just as much as an FPGA-based 68000 compatible CPU is.
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Old 01 June 2016, 16:55   #286
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I agree
But I would like to hear a consistent logic and explanations from people who so easily decide what is and what isn't an emulator.

Everyone can see my explanation on the last page. I would like to hear a different method of concluding.
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Old 01 June 2016, 18:09   #287
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/Ops (sorry for the off-topicness)

There is a monumental difference that would take an entire thread in itself to clarify the difference between emulation and field programmable arrays - but in short

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Originally Posted by demolition View Post
I don't like the word either as it can be misleading but depending on which definition you take on the word, it is not entirely incorrect that an FPGA implementation of a 68000 is emulating a real 68000. Using that definition, a 68020 is also emulating a 68000 since it can run most of the same software but is not a real 68000.
I am sorry my friend I have to disagree on this point - a silicon gate is just a logic gate - a field programmable device is just that a set of logic gates - that process exactly the same as any processor - there is no emulation - to call it that can propagate an underlying lack of knowledge to what a processor is - which is simply a set of logic gate blocks

The only difference with FPGA's (Field Programmable Gate Arrays) processors and ASIC (Application Specific Integrated Circuit) processors is that logic gates are volatile and require a load of its gate arrays on power up.
You would still call a ROM a ROM if it was written to a electrically erasable read only memory (EEPROM) or on a one time programmable read only memory (OTPROM) - one is not emulating another. Should I now bring up MASK ROMS?
Besides most ASIC devices over the last donkeys age have been developed from both Complex Programmable Logic Devices (CPLD's) and FPGA implementations - I suspect that the Vampire could go in that direction if there was a large enough market.

FPGA (why)
Rapid development of processing features
Debuging and refinement
Expensive in single quantities[*]


ASIC (why)
Cheaper to produce over large quantities
Generally higher clock speeds
Large minimum order quantities
Errors are propagated throughout the production run


[*]FPGA's have become both inexpensive and more complex allowing for specialist equipment (low volume) to be produced for various markets - the retro-computer scene has been one of these for some time.

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But when most people here hear the word emulation, they think of software like WinUAE, and that is something completely different so I'd also prefer to not use the word emulation in conjunction with FPGAs.
Just think for a moment the level of abstraction here - there is the kernal hardware layer, there is the communication layer and there is the operating system layer, then there is the software layer - which in the Case of UAE arguably repeats this again through approximation.

In most cases software Emulation is very much removed from the hardware

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"It still isn't a 68000."
So it's an emulator ?
No, it is a 68020, it has the same logic gate instructions as the 68000 (some more refined) plus additional instructions - it is a completely different processor - one that can manipulate data in 32 bits instead of 16

Of course, all in all we are only arguing what the root meaning of a word used in a given context e.g. computing - From this context I would ague that emulation is approximation through many layers of software - that does not mean emulation cannot match or surpass its intended platform as in a lot of way's WinUAE has shown us that is has.

FPGA's are not not emulation, they are an implementation they do not have processing overheads associated with the most commonly understood software emulation.
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Old 01 June 2016, 18:39   #288
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Quote:
Originally Posted by Lord Aga View Post
"It still isn't a 68000."
So it's an emulator ?
No. It never claimed to be a 68000.
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Old 01 June 2016, 18:44   #289
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So when did the Vampire FPGA or new graphics card's FPGA claim to be an original 680X0 CPU or the original graphics chip ? As far as I know they only claim compatibility.

I'm really trying to find some logic in your posts but you're not making it easy.

Last edited by Lord Aga; 01 June 2016 at 19:06.
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Old 01 June 2016, 18:50   #290
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Quote:
Originally Posted by Zetr0 View Post
The only difference with FPGA's (Field Programmable Gate Arrays) processors and ASIC (Application Specific Integrated Circuit) processors is that logic gates are volatile and require a load of its gate arrays on power up.
[INDENT]You would still call a ROM a ROM if it was written to a electrically erasable read only memory (EEPROM) or on a one time programmable read only memory (OTPROM) - one is not emulating another. Should I now bring up MASK ROMS?
Back when console games were delivered on ROM cartridge, developers used "ROM emulators" to transfer and test their games on consoles. Using volatile memory.

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Originally Posted by Zetr0
FPGA's are not not emulation, they are an implementation they do not have processing overheads associated with the most commonly understood software emulation.
It seems that the word "emulation" has become a red herring in the Amiga world. A lot of us dislike emulators, and those who make FPGA reimplementations want to avoid the ugly connotations of the "E word". But in the end, an emulation is an apparatus that mimics another device. If you implement a well-known graphics chipset in a general-purpose device such as an FPGA, you are emulating it. If you deviate too far from the original (like the Vampire does, but the MiniMig doesn't) you can make a case that you're not emulating. But emulation is just a word, it's not a set of rules that say you must write a 68000 in C.

So, in conclusion, AlexH was using the word correctly when writing this short message, which led to an entire page of debate over the word "emulate":
Quote:
Originally Posted by alexh View Post
If the FPGA graphics card designers were to emulate the GD5446 register set they wouldn't need to write or include a driver with their hardware.
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Old 01 June 2016, 18:55   #291
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Quote:
Originally Posted by idrougge View Post
an emulation is an apparatus that mimics another device.
So the 68020 IS an emulator after all ? A completely different piece of silicone emulating another device (68000) when you start, say, Bubble Bobble.

What is not an emulator then ? Only the 68000 CPU ? Only the first 68000 ever produced ? Only the very first working prototype of the 68000 CPU ?
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Old 01 June 2016, 19:05   #292
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Isn't this "emulation" debate a bit off topic? It's already eating pages in this P96 licensing thread. If you are picky enough to spend pages to debate what constitutes emulation maybe you can appreciate that some ppl will be picky about discussions respecting the thread topic. :-)

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Old 01 June 2016, 19:08   #293
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It would be great if the moderators could move this to a separate thread.

These emulation discussions pop up from time to time and we need things to be clear enough.

Call it "FPGAs - emulation or not"
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Old 01 June 2016, 19:13   #294
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If I implement my own CPU and include the original 68000 instruction set (as well as adding new ones) I am certainly not emulating it, but keeping compatibility with it.

Same thing with Intel CPUs that came after the 8088 (used in the first XT). They could all run 8088 code but included many new commands (I'm referring to 286/386/486 etc).

That's called being back-compatible, has nothing to do with emulation.

(Sorry for continuing the OT discussion)
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Old 01 June 2016, 19:41   #295
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Emulation should be the correct term to use, albeit perhaps not appropriate because it is associated with "Software Emulation".

I used it because anyone re-creating a GPU or CPU today does not re-create the design in the way it was originally implemented. It is never a gate-for-gate recreation. Normally they are not even 100% logically equivalent. Not enough information exists on the original design and technology has moved on. It just has to look like the original from the outside world and how it works under the hood can be and usually is completely different. They emulate the behaviour of the original.

P.S. I'm an RTL design engineer writing VHDL and (System)Verilog for use in FPGA and ASIC on a daily basis for the last 16 years. We have always called the use of an FPGA for a design which hasn't gone to Silicon "Prototyping" and using an FPGA to re-create a design which has been lost (or chips which are no-longer available) as "Emulating". But it gets confusing as there is such a thing as an Emulator for prototyping too where the design is modeled in software on thousands of processors.

But it is just the ambiguous nature of English language.

Last edited by alexh; 01 June 2016 at 19:51.
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Old 01 June 2016, 20:04   #296
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Quote:
Originally Posted by UberFreak View Post
Same thing with Intel CPUs that came after the 8088 (used in the first XT). They could all run 8088 code but included many new commands (I'm referring to 286/386/486 etc).

That's called being back-compatible, has nothing to do with emulation.
It is being backwards compatible by emulating the old hardware. It has everything to do with emulation. It may not be a software emulator, but it doesn't have the original design inside -> it is an emulation.
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Old 01 June 2016, 20:06   #297
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See, it's not so easy to define emulation

As I said earlier - either everything is emulation, or nothing is Except for WinUAE of course. That always is
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Old 01 June 2016, 21:52   #298
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See, it's not so easy to define emulation
Sure it is. Look in an English dictionary. This is the generic definition for emulation which we can't re-define. An FPGA can exhibit this behavior called emulation. A tech variation of the definition for emulation is also now in use (meaning software emulation, perhaps more) but most dictionaries do not include tech definitions unless they are very common. Using the word emulation now is like using the word Jew where it could be talking about a race or a religion (or even the people of a geography like Judea or Israel). The use of the word need only be correct by one definition even if loosely correct. It is often better to use another word without these problems in these situations. IMO, the more concise word to use for what an FPGA does would be simulation.

Quote:
Originally Posted by alexh View Post
If the FPGA graphics card designers were to emulate the GD5446 register set they wouldn't need to write or include a driver with their hardware.

I believe the hardware is well documented, and has been emulated in open source software.

Any patents covering this hardware design will have expired
Emulating the chip set is not enough. It would be necessary to emulate one of the graphics boards using it in order for P96 to find and start using the chip set. If there was an open driver like OpenPCI for it then it would be possible (would requires a new pci.library). An FPGA has no PCI but it would not be a problem to emulate the PCI structures. The Prometheus documentation is pretty good. Perhaps even its implementation of the pci.library could be used if the PCI was simulated well enough. There are some newer cards which have documentation which could be evaluated also. Of course, bolting on a PC gfx card to get chunky is a kludge in the first place. The AmigaOS should support RTG chunky (actually AmigaOS 3.9 already partially does). AROS is an option which could avoid this problem. It looks like the guys at A-EON are just fair weather 68k Amiga supporters so instead of enlarging the AmigaOS camp and proliferating their APIs (P96, Reaction, etc.), we will have to enlarge the AROS camp and proliferate their APIs (CGFX, Reaction, etc.). It would help if the FPGA guys would adopt standards for chip set and CPU enhancements which would make support easier. Maybe Heiroglyph has some ideas which will help bring AROS (especially RTG) to the 68k in a more acceptable form. So far, we have had trouble bridging the gap from AROS x86 to AROS 68k on classic hardware.

Last edited by matthey; 01 June 2016 at 21:59.
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Old 01 June 2016, 22:14   #299
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Maybe Heiroglyph has some ideas which will help bring AROS (especially RTG) to the 68k in a more acceptable form. So far, we have had trouble bridging the gap from AROS x86 to AROS 68k on classic hardware.
I'm still trying to work that out, it's a big job and it's looking more like patches like the original Cgx and P96.

As for Fpga, if you make a card that looks just like the original chip, you're stuck with only the capabilities of the original. The driver can't do anything more than that.

Same small amount of memory, acceleration functions, etc. just somewhat better availability and maybe some small performance improvement if we're lucky.

That's very limiting considering it's not a technical problem but rather a problem that was purposely created for us.
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Old 01 June 2016, 22:18   #300
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It is being backwards compatible by emulating the old hardware. It has everything to do with emulation. It may not be a software emulator, but it doesn't have the original design inside -> it is an emulation.
I guess we'll have to agree to disagree
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