No, it is not Commodore 64 anymore. It won't feel like one, you can as well run an emulator. I get it, FPGA is more faithful reproduction, than pure software, but it is not a real thing, and will never be.
The logic could as well be implemented in software - the reason it isn't and it wasn't in the original C64 is because it was not possible then. Programming this logic on a CPU would have required a very fast microcontroller, that would probably be more expensive than the whole computer. Even today, not many MCUs would be capable of emulating the CIA and keep up with all the timings. Mind you there is a difference in creating a software emulator that runs within the host computer versus emulating a chip that responds in real time to the electric signals.
Aftermarket / modern replacement parts cater to a different market. They don't 'dilute' the historic value of original parts.
There is considerable overlap though. If anything, availability of modern replacements eases demand for original parts. Helping to keep those available for purists, musea, reverse engineering etc (and their prices reasonable). This should make both purists & non-purists happy.
In any case a "Commodore 64" made entirely from components invented in 2020s should be called C64 anymore. It is a replica, a decent one, but not the real thing.
Want to have it collecting dust in a museum? Sure, you're going to want the original. Nobody is interested in an FPGA for that.
Want to actually use it? If an FPGA is close enough that it is literally impossible to tell the difference in a black box comparison, for all intents and purposes it is the original. Emulation simply isn't accurate enough for that, but FPGAs can be 100% cycle-accurate. And this means you don't need to risk wear or damage on your genuine C64 just to experience what it is like to use a C64.
Put another way: You can pull an 8520 from an Amiga and put it in a C64 and most users will never know the difference (been there, done that, horrified my parents who saw me involved in surgery on our two computers) because most C64 software never uses the clock function of the 6526. As long as it provides the IO functions you mostly rely on, most users will never know nor care about the difference.
> Replacing original parts with microcontrollers would take away a lot of that pleasure.
Why, when these parts react to the same electrical signals in the same way? In this case it's also not a microcontroller but an FPGA. The contents of the package is different, but the contents of the package also changed during Commodore's own production runs e.g. the change from 6526's to 8521's.
First of all neither FPGA's nor MCU are not going to "react the same way to electric signals", cause contrary to what many think, FPGA's are not tabula rasa you can put any digital design to - there are limitations to what can be synthesized. Secondly, 6526 to 8251 is not only period correct, but also a change made by manufacturer themselves, therefore has almost zero historical impact.
There is no way a new design, with almost everything replaced by FPGA's can be called Commodore 64, as much as a Ford-T with a brushless electric motor and lithium baterries can be called Ford-T. You can call it replica, and sell it to those who to pretend they own a historical car, but for everyone who truly understand value of old and antique, that would be laughable.
No, I understand it, but yes, I think it is absolutely bizarre. Both can be true at the same time. To me the value in an original over a replica is purely whether or not a bunch of purists are willing to pay more for the original, which I find both bizarre and hilarious. To me the original has no additional value over the resale value - if anything it's value may often be lower if I suspect its age means a higher risk of having to replace components down the line. So, sure, if I were to buy one for the sake of potential financial value I'd value original, working parts because I know some proportion of others care. But if I bought one to use and found some parts had been replaced, I wouldn't stop calling it a Commodore 64 whether or not the replacement parts were original.
But in this case, the price for a Commodore 64 is still low; not even purists are willing to pay much for them.
> First of all neither FPGA's nor MCU are not going to "react the same way to electric signals", cause contrary to what many think, FPGA's are not tabula rasa you can put any digital design to - there are limitations to what can be synthesized. Secondly, 6526 to 8251 is not only period correct, but also a change made by manufacturer themselves, therefore has almost zero historical impact.
For the fidelity required for a 6526, it very much is reacting close enough or it wouldn't work as a drop-in replacement. I don't care if there's some sort of deviation that is small enough that it has no relevance to it's correct functioning in the real hardware. As for "period correct", I couldn't give the tiniest little shit, as the long as it works, as unlike the SID or VIC, there's no "works correctly but the output is different enough to affect my enjoyment of the machine".
> There is no way a new design, with almost everything replaced by FPGA's can be called Commodore 64, as much as a Ford-T with a brushless electric motor and lithium baterries can be called Ford-T. You can call it replica, and sell it to those who to pretend they own a historical car, but for everyone who truly understand value of old and antique, that would be laughable.
Of course there is every way in which something with everything replaced can be called a Commodore 64: All it takes is people choosing to do so. For me, whether or not I'd call it a Commodore 64 would come down to a subjective assessment of how similar it is. If you changed the physical appearance, that'd be a no for me, but replacing a part that doesn't affect the way the machine works? Sure. I wouldn't try to pass it off as an original, but I also wouldn't care one bit that it's not original, because I don't have any interest in a "historical artefact" but in the nostalgia of being able to use something which feels like the original.
Enjoy your electric Ford-T!
A connection to history is irrelevant to me. Something which triggers my nostalgia and which I enjoy using is not, and that does not require perfect accuracy (if anything, nostalgia often favours avoiding perfect accuracy on favour of avoiding nuisances)
I certainly do have no interest in "investing", no, because investment or history is not the point to me.
If I had the choice between an electric Ford T and an authentic one, I'd certainly prefer the electric one. That's be an interesting curiosity - Ford worked on one which was never launched, and his wife drove an electric car -, while an original one would be something I'd have no interest in outside a museum.
BTW, good luck reselling your model T as actual model T LOL.
Reselling an actual model T with an electric motor as an actual mode T with an electric motor would work just fine. Some would lose interest because it's been changed, some would find it more attractive. For my part, I'd find it far more interesting and be willing to pay more for something esoteric like that.
Using the actual hardware with 100% accurate modern part replacements is one way to get there. Another way is to have perfect, "cycle accurate" emulators but these aren't easy to come by - some emulators have been in development for years and still have glitches. This kind of hardware replacement has a much higher chance of reaching the 100% accuracy I'm referring to.
There are other similar projects. This notion that the use of FPGA's means there's some inherent difference in fidelity that newly made silicon wouldn't have is nonsense for parts like this that are so far from pushing the limits of available FPGA's.
Arguably an emulator could do the same, but it's much harder to simulate the entire system than it is to isolate a single chip and emulate that.
But also keep in mind that there is no such a thing as a "digital circuit" in physical world, because there some analog effects at work in any digital circuit. If it were not true, the would not have been hardware incompatabilities seen even in moderrn systems, which often happen due timing/delay or noise issues. WRT to retro tech, in for example Apple-I modern 74hct/act chips would not often work compared to more humble 74ls chips. There are also interesting temperature-dependent effects in NMOS 6502 (some undocumented instructions are executed differently) which have non-digital reasons and cannot be reproduced.
Emulators are a lot easier btw to write than a VHDL or verilog spec and put it to actual hardware and debug etc, due to having already so many existing open source code for emulators, processors etc.
My point is different though - there is no way to make new Commodore 64 out of existing components. What you will get is a faithful replica with zero historic importance. For some it does not matter, but I still believe that even these people make a majority, the resulting product is not C64 and should not be called such.
1) The historical artifact. Case manufactured in original factory, IC's manufactured back in the day under (in this case) Commodore's supervision, etc.
In this case,"original condition" is paramount. Some may be happy with minor fixups like replacing electrolytic capacitors, power supply, broken connectors, replace dead IC or whatever. Some may want as original as possible, in working order or not.
2) The look & feel, having original-looking machine in front of them, that (as much as possible) connects to the same peripherals original machine does. And runs software exactly like original machine would.
In this case, most buyers won't care (or even prefer) various upgrades / replacements, as long as that look & feel remains. See eg. CPLD or FPGA based replacement parts, new keyboards, or "mini" versions of systems like the NES. That C64-in-a-joystick or similar is grey area here. :-)
I suspect user group pursuing 2) is larger than those pursuing 1). Let alone the purists among them.
Software emulators are just a lower-bar, easier way to tip one's toes in the water (or do sw development).
In any case I would agree with title "100% new C64" if it were made from silicon level replica of chips, not FPGA's, much like new 6502 sold on aliexpress are generally good replicas of NMOS 6502, with the quirks and even current consumption faithfully reproduced, not some Xilinx Spartan-based simulacrum of the real thing.
The newly-made design, be it in FPGA or ASIC form, is not the original MOS chip. But it could indeed behave identically.
ASIC advantages such as lower power consumption and higher achievable clock speeds at a given node, are advantages relative to the FPGA. Not advantages relative to the original MOS chip, which dirt cheap FPGAs can vastly outdo, and only need to match for the purpose.
Honestly it would have been cool if they added a battery and maybe an extra register to indicate its presence; having the TOD clocks keep their time between power cycles would be cool.
Edit: If replacing a dead 6526 I would keep the dead one too. :)
FPGAs are not emulation. They implement logic at just as low a level as an ASIC. One day even working original C64s will stop working. You can't get original parts anymore. This is as good as it gets for fixing those.
But I get it, it’s really hard to accurately replace legacy components as time moves on, it probably will feel like one but as it’s not all original it will never meet an unattainable expectation.