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J-CIA64 – Modern spare part for Commodore 64, Commodore 128, SX-64 (1nt3r.net)
225 points by dusted on Aug 9, 2023 | hide | past | favorite | 133 comments



Tangentially related, and given some of the debates in the comments below, I'm sure I'll be burned at the stake for this, but here I go anyway:

I've given up on owning a real C64, just to remind me of my childhood. It's too convoluted, requires buying replacement parts, and I don't own any TV to plug it into. VICE emulation is good enough for me. But I really wanted the keyboard, which was a major part of the experience for me.

Out of the box -- no soldering, not buying extra cables or expansions or add-ons -- the most feasible option for me was buying the retroremake TheC64 ("max", the full version with the working keyboard).

Is it perfect? No.

Is it a C64? No. It looks like one, but inside there's an ARM chip running VICE.

Does it look like a convincing C64 "breadbin", and can I play every game, type BASIC programs, play with PETSCII art, even type assembly code, and generally relive my childhood?

YES!


I'll plug the Ultimate 64 (https://ultimate64.com/Ultimate-64-Elite) — it's a hardware-emulated C64 that you place inside your breadbin case. It works unbelievably well and is a great modern replacement with a lot of convenience added. For example, you don't have to deal with weird PSUs (12V runs it just fine), you get a HDMI output with sound (can be from a real SID!), and the HDMI out has no delay. That's a big deal: all the emulators normally use framebuffers, so you get a delay, none of the games were built for it.

What I find great is that you can plug in a USB stick with all the C64 games ever made and just load them quickly up using the Ultimate 64 built-in software.

I have both "real" C64s and the Ultimate 64, but I only use the Ultimate these days. It's just easier.


The problem is that the Ultimate 64 has been out of stock for a very long time. I check every few months, and have never seen it available.

And even when it might be available, you can get two or three real C-64s from eBay for the same price.


Sure, but add to that a modern storage solution (ideally a 1541Ultimate 2+), a lag free scaler (like the RetroTink 2X), and a modern power supply. The U64 comes with all of that built in.


Thanks! It looks awesome and better but also more expensive (and slightly less "out of the box") than TheC64, at least when I got mine.


I enjoy owning the fourth earliest serial number C64 registered on the C64 registry, and last I tried it still worked. But honestly I wouldn't ever really think of actually using it or any of the handful of others I have. Whenever I'm in the mood to play, I use an emulator.

And this basically goes for all the old nostalgic hardware I've got. For kicks I booted up an old Sun 3/80 I picked up a bit ago. After replacing the failed hard drive with an SSD on an adapter board, figuring out how to regenerate the boot info on a replacement of the dead battery backed RAM chip, and getting it to actually net boot off a Linux host, I realized SunOS 4.1.1 is a lot more of a pain in the ass than I remembered from back in the day. It was an amusing adventure, but it did make me think twice about trying to boot up my old SGI Indigo.


It's really awesome how different people are able to engage in this hobby with different requirements.

For me, working on a real 64 is essential but I don't care about disk drives at all. So a Commodore 64 + Ultimate II+ (or pi1541) is a great combination. I love being able to use real 64 joysticks with no lag.

Keeping the hardware going is half the fun - I have replacement chips for everything on the board, diagnostic carts and have enjoyed picking up soldering again.

For Assembly language programming though, Visual Studio Code + Kick Assembler + Vice + C64 Debugger all the way!! Makes the development and debugging process completely seamless.


I don't think anyone will burn you at the stake! Real hardware is great for diehard enthusiasts, for those wanting to use old peripherals, and for people wanting to play with electronics. Emulation is great for nearly everyone else.


I'm also a THEC64 owner, and I call it "retrocomputing on easy mode". That's a good thing! It offers a good-enough simulacrum of what the C64 experience was like. The breadbin case with original-layout keyboard, which feels plausibly like one of the keyboards that shipped on actual C64s (there were a few different ones), really put THEC64 over for me. And it just works with modern equipment like HDMI displays and USB controllers. It's a great way to introduce kids to the way we computed back in the before times.


> I've given up on owning a real C64

I can understand that... I'm lucky in that my very own C128, after nearly 40 years, still works. I think the C128 is a bit easier to get going because the PSU are of much better quality than the C64's PSUs and IIUC the C128's PSU is less likely to destroy the computer should it malfunction.

I wrote it recently in another thread here on HN: I've got both original PCBs from the eighties and a Raspberry Pi in a vintage arcade cab and it's pretty much giving identical results (except for the boot procedure).

Emulation may not be the real thing but it really became close enough.

We have options and we should be happy about it.

And as my electronic and soldering skills are really mediocre, I fear the day where my C128 shall eventually give up.


You can also use TheC64 (Max) as a USB keyboard to the PC to use in Vice if you decide you want the keyboard and want to take advantage of some of the functionality of the emulators. I found a page that shows how to add a USB connector to the Max to allow this.


Never thought of this. Looks useful! I will look it up.


Much like how I've gotten onto a PDP-11 kick - yeah, it would be neat to have my own 11/70, but the power and space requirements would be insane, I'd have to track down rare and expensive pieces, and I don't have quite the skill set to debug/repair old hardware to the component level. SIMH it is (and it has a zillion other emulators as well).

Modern hardware can emulate an 11 much faster than any real one ever built. RSTS/E installs in seconds when your "disk" is NVMe and you don't have to wait for a DECwriter II console at 30 cps.


You may wish to consider the PiDP-11, a frame that replicates the PDP-11's blinkenlight panel, into which a Raspberry Pi running SIMH or similar can be installed. Attach a terminal with a USB-to-serial adapter, and the experience is complete, without the drain on power, space, time/effort, or money. It's like THEC64 for the DEC mini world.


MiSTER is pretty much a perfect replacement.


Curious: does MiSTER have a fully working C64 keyboard lookalike with no extra work that I must do, out of the box? If not, it's not what I was looking for :)


I did see a project to convert one of those remade c64 boxes into a mister case somwhere. let me google … oh wait, google is useless now.


A Pi400 is also an excellent option in my opinon. I love doing both real hardware and emulation for different purposes, I don't see anything wrong with picking either, neither or both (neither of course is the worst option ;) )


I considered the Pi400 but, like I said, the C64 keyboard was a big deal to me. Otherwise I would just use VICE on my laptop :)

Yes, I know: you can get custom keyboards, or print labels and stick them on a PC keyboard, or 3D print a case with a working keyboard: all of that is either more involved, more expensive, or fiddlier than what I wanted.

I wanted an out of the box experience with a working replica of the keyboard, complete with PETSCII symbols on the key caps, and TheC64 delivers just that :)


I like both. The software is so much more convenient with emulation, but seeing the real hardware feels like it takes you back in time...


TheC64 goes a long way into fooling you. Barring minor details (especially in the connectors and peripherals) it looks like a real C64! It delivers most of the nostalgic experience for me.


I question why people go through the trouble of doing this. Then I remember back to when I was a pimply teenager, lugging my C64, 1541, and 13" TV to a user group meeting on a crisp Saturday morning. We would share warez and see awesome demos and oogle the C128's and inevitably someone would bring an Amiga. We'd gather around while they played the latest games and show off the full capabilities of that machine. We had some Apple users there too with their IIe's and IIc's. I never saw a Mac in real life until much later in college. And that's a part of my life I'll likely never live again, but now I get why people want to build these machines today, for nostalgia.


I still remember the first time I played a couple of Psygnosis games on an Amiga 500: Blood Money, and Shadow of the Beast. Those two blew me away. The sound and the graphics were absolutely stunning for late 80's.

I have a MIST, Vampire board, and still play around with UAE from time-to-time... but there's nothing like seeing the "real" hardware for the first time when you were a teenager. Even with all the hardware I've had over the past 30 years, everything else has felt so incremental.


>And that's a part of my life I'll likely never live again

Back then, very few people had these. Now, nearly everyone has something much much more powerful in their pocket/purse or on their wrist.

I do pity younger kids today not having that feeling. The was a mystique around them. Now, it's just part and parcel of everyday life. Everything new now is just an upgraded version of something prior. Back then, it was all so new. I can't think of anything that would have the same feeling for kids today.


Assuming continued forward progress, this feeling is true of each generation. But when I get nostalgia about all the progress the world made since my early childhood in the 80s...I think about my great grandfather who was 8-ish when the Wright Brothers made their first flight, 40s when the atomic bomb was developed, 73 when the first man walked on the moon, and then lived another 20 years!


Not just nostalgia. I want to experience what the first personal computers were like. I think there's a lot of value there!


I also believe there’s some value in reassessing how systems like that function. There’s some value in a challenge like: what can you do on older hardware with todays knowledge? Maybe there’s something to be learned and applied to modern problems.

Also, it’s a good introduction to understanding full systems, from the electronics—soldering, voltage, current, etc to assembly programming. The system is simple enough for them to ship circuit diagrams in the developer manual—along with all the opcodes and kernel routines.

There’s a resurgence across all fields in artisanal craftsmanship. Carpenters, blacksmiths, printmakers, cobblers.

Retro-Computing is exactly that—artisanal electronics and programming. There’s something meditative and enjoyable about it.


I think an underappreciated value of growing up in that era, was that the entire machine, top to bottom, was simple enough that a single person could understand it. Without even making it their life's work. There's simply nothing today like that.

So the older machines are an important conceptual building block. And they're not academic exercises taught in theoretical simulation but never experienced, they're real physical machines that did useful things for people who are still around and can walk you through doing the same things on the very same machines.

The other magical thing about home computers of that era, was that they were ROM-based, with very explicit operations to commit data to nonvolatile storage. You couldn't accidentally delete a system file and render the machine unbootable, and that encouraged experimentation in a way that subsequent PCs harshly punished.

Also, while 8-bit home computers weren't really toys, they were _almost_ toys, in that very few folks were running a business on their C64. (And again, even if they did, all they had to do was lock the business disks in a cabinet at the end of the day.) So the consequences of even a major screwup were limited, again in a way that the next generation of PCs dramatiaclly reversed. I knew kids "grounded for life" (actually a few months) in the 90s because they hosed up the family PC that mom or dad was doing the taxes on or whatever. That simply wasn't a thing in the 80s.

All of learning is making mistakes. One hundred percent. And modern machines don't allow it in the same way. We were privileged to learn in a real-but-nearly-consequence-free environment, which today's kids will simply never experience.


The Commander X16 and Foenix F256K are new machines that you could comprehend completely. I don't really want to call them modern though.


Agree. I was born way after the C64 came on scene and never touched one until I bought one ten years ago. I'm in it for the perspective it brings (and I like fixing things).


Retrocomputing isn't just about nostalgia, a midlife-crisis rewind back to your pimply-faced youth. People are still getting more out of those old systems than was ever thought possible back in the day, using powerful modern systems to solve for packing ever more complex code or data structures into 64k or less. Kids are being introduced to old platforms. They can't deliver the graphical fidelity of the Xbox Series S, but if Minecraft and Roblox are any indication, post-zoomer youth do just fine with simple, abstract, representational graphics.


I think I've plugged this before, but I have bought the part and it's working in my "MaxFake64" project, only thing left from Commodore is the keyboard http://dusted.dk/pages/c64/MaxFake64/


Very cool project! I hope you do the keyboard too, because (in my opinion) that's the worst part of the C64. I see you're building the C64C form factor. I don't know if that has a different keyboard than the bread bin I have, so maybe yours already has a better typing experience than mine. And even if it's the same keyboard, the lower profile of the case must already make a huge difference. But building a nice keyboard for it with good switches will still make a big difference.


I'll definitely do the keyboard, actually I'm using the breadbin keyboard here because I think it looks neat. Commodore were pretty good at keeping things compatible. The motherboard was intended for breadbin as well, but fits fine in the C case.


How do you like typing on it? I wonder if I dislike typing on my breadbin only because of the height of the case, and the position it puts my wrists in.


I find it perfectly fine and acceptable for long periods of time, I think the original keyboard is quite good mechanically (springed keys with conductive rubber feet onto pcb pads), the ergonomics of the breadbin (I have an ultimate64 and a few real ones) is not my cup of tea, it ends up hurting my wrists after longer sessions, no such problem at all on the C64c models.


Hmm maybe I'll put a C64C on my list of "things to buy if they happen to pop up at a reasonable price".


I have a boxed C64 that hasn't been turned on for over 20 years

I thought I'd try to turn it on but got spooked by the requirements for the PSU

I understand it needs ripple free 5VDC 2-4A+ through a 7 pin din

Am I really going to blow the unit up with a switch mode, does it really need linear regulation?

What's stopping me using 2-3 LM7805s in parallel?

[Background] former burnout frontend dev working at an electronics shop


You can do it with a linear supply, a common mod that people do is actually to replace the lm7805 regulator with a pin compatible switching replacement for less power draw and heat generation.

I think ripple-free is by 1982 standards ;)


The PSU also supplies 9V AC (this is not a mistake). The C64 is quite sensitive to over-voltage, so your switching supply might work, or it might kill it because there are voltage spikes which modern equipment doesn't care about, but the C64 will.

The PSU situation isn't great: building your own is difficult (see https://www.c64-wiki.com/wiki/Power_Supply), and using an old "real" PSU is risky, because they tend to produce >5V as they die, taking the C64 with them. That's why I ended up using the Ultimate 64 rather than a real C64: just supply it with 12V DC from basically anything, and it will be fine.


You are probably aware, but replacement PSUs are fairly widely available [1].

I am no EE but I would be very surprised if they are linear.

[1]: https://www.c64psu.com/


Edit: Do NOT use LM7805s in parallel, they don't load balance evenly


Why would you blow it up with a SMPS? I built a PSU for mine with a 5V switch-mode wall wart that originally powered a USB hub and it works fine. There's a 100uf filter cap on the 5V rail inside the machine already that will smooth things out. The real danger is letting the 5V rail get too much over voltage; that's what happens with the original power supplies, and it will cook the RAM chips in a hurry.


Can't you just use some filtering caps? (spoken as a non-EE)


What do they do about the SID?

For younger folks, the SID is the sound chip of the C64. It's infamous for being partly an analog circuit. That is, it uses transistors in states between 0 and 1, as you would in a transistor-based amplifier, or an analog radio. This gave the sound of the C64 its unique texture.

My understanding is that this behavior is impossible to reproduce with modern chip fabrication techniques, so what's the solution? Digital emulation?


That's not true: you make the SID sound weird and exotic when it's really not (although it is incredibly cool).

Seen from the perspective of microcomputers, which mostly either used simple square waves, or FM synthesis to generate sounds, the SID is unusual. But seen from the perspective of sound synthesis the SID is an analogue subtractive synthesizer[0] which, at the time of its design, were commonplace. As I say, that was pretty unique amongst microcomputers, and is why the SID was and is revered by fans of the 8-bit era: it has a really fantastic, crunchy analogue sound, that other computers of the era just don't and, indeed, can't reproduce.

I'd go as far as to say that Commodore missed a massive opportunity with the Amiga in terms of use for music: if it had the PCM based Paula chip, plus a SID chip (or even two - a man can dream), it would have been absolutely incredible.

In recent years analogue synthesizers have experienced something of a resurgence although, in truth, they never completely went away. As such ICs with analogue circuitry are actually relatively commonplace. Now that doesn't mean you can just remanufacture the SID chip really easily, but it is absolutely possible to build ICs with analogue circuitry today: as a trivial example, analogue to digital converters are commonplace.

[0] I think strictly speaking it's also a paraphonic synth, since all the voices share a single filter, but I can't remember off the top of my head whether they also all share a single amp (again, a hallmark of a paraphonic, rather than a true polyphonic, synthesizer).


It actually is weird and exotic. The analog SVF filter is made with digital components and is highly nonlinear. No one fabricates these any more though it would be technically possible.

Emulating the distortion is done with varying levels of accuracy.

Additionally the fabrication varied from part to part and from rev to rev. So the sound of any SID is a combo of its batch of substrates limiting bandwidth and the intermodulation distortion (IMD) of its FETs' imperfect emulation linear adding and multiplication functions increasing the bandwidth. Note that these non-linearities are in a feedback loop.

Furthermore the external caps ("matched") used for the filter varied considerably, but this is more easily reproduceable.

The envelopes are unconventional too, but more easily emulated than the filter. They are a mix of linear and exponential and use the non-linear FET multiplier.

Also the oscillators are not simple analog oscillators. They're high frequency lookup tables with digital aliasing related to the key the music is written in. The noise waveform is not analog, either, but a variable frequency LFSR, although this is easy to reproduce in FPGA and somewhat in software, although the max frequency can be challenging.

Finally the entire signal chain is replete with IMD so any melody/rhythm played on one voice is affected and influenced by what is played on the other voices.

In summary the SID was designed by electronic musician Bob Yannes who modeled it after typical analog synths but was technically limited by the fabrication of the age to make it less clean than even the grungiest cold war soviet synth. Still it was better than everything else at the time and it got a lot of loving attention from devs and musicians who squeezed every ounce of juice from it.


> I'd go as far as to say that Commodore missed a massive opportunity with the Amiga in terms of use for music

IDK - the first DAWs were made for the Amiga. If the Amiga hadn't already died-out by the early-ish 90's then I'd imagine Pro Tools would have been created on that and there would be a very real possibility we'd still be using Amigas today.


Didn’t the Atari ST own the DAW space at that time?


The ST ate everyone else's lunch (in the DAW world) because it had built-in MIDI.

In a world where the Amiga didn't need an external MIDI interface, I suspect things would have been different.


Well, they did have Creator which went on to become Pro Tools. As I recall, its big thing was MIDI sequencing whereas the stuff for the Amiga was more content creation-oriented. Add in the fact that the Atari ST was cheaper and I guess that was that!


It did. Reasons are

1. Built-in MIDI interface.

2. High-resolution screen available, 640x400, 60Hz monochrome.

3. Simplistic operating system, the DAW software had 100% control of all hardware and timings.


640x400 71Hz


Digital emulation, yes, like the ArmSID[1] which lets you tune the output to what you expect a SID to sound like, because they didn't all sound the same either, which is part of the problem of "accurately" replacing it - they were never accurate to begin with.

[1] https://retrocomp.cz/produkt?id=2


They were accurate, just not precise. ;)


It's not impossible. We still make many analog chips. Opamps, power amps, signal processing.

What's difficult is replicating it with generic programmable platforms like FPGAs because those are mostly digital gates.

But if we'd just want to cook a bunch of SID chips that's no problem. It'll just be hard to get enough interest to warrant all the design and setup work. You'd need to do a large batch to make it worth the investment.


I'm personally pretty happy with the ArmSID, thing is, it does not sound like my 6581R3.. BUT! My 6581R3 also does not sound like my other 6581R3, there's not really any "one true" sound for the SID, for better or worse.

That said, if I were to do music production, I'd use my real chip, because I prefer the sound of it.. But, on a PC, I'd use one of the libraries, like libsidplay which emulates the sound better than the ArmSID.

The same could be said for the VIC2 chip, I've yet to encounter two that give the same image, they look slightly different. There, I do prefer the look of the kawari on s-video, it's just.. easier to see ^_^


> BUT! My 6581R3 also does not sound like my other 6581R3, there's not really any "one true" sound for the SID, for better or worse.

Might just be old age? At some point, IC's may be degraded to a point where few (if any) work exactly like original part when it was new. And thus also differ between specimens.

At some point, original parts may become unreliable / quirky / glitchy enough that picking some kind of re-implementation (rather than original) as the "gold standard" is the only way forward.

Not a big issue for 'pure' digital parts like CPUs, glue logic etc. But (partly) analog IC's like sound or video chips... different story.


I guess we can never know, but I strongly suspect they've never sounded the same, similar, but not the same.


If you enjoy this stuff, https://c64audio.com/ is well worth a look. Some good stuff from only 25 years ago at https://archive.org/details/back-in-time-1/Back+in+Time+1/Ex... .

I was really into Koyaanisqatsi at the time and you'll definitely hear the influence there.


A bunch of folks mentioning ARMsid, but there are a number of FPGA-based implementations as well:

FPGASID - https://webstore.kryoflux.com/catalog/product_info.php?produ... reDIP SID - https://github.com/daglem/reDIP-SID


Am I the only one with a twang of dread and anxiety... being transported back to a summer weekday in the 1990s. I was maybe 8 years old, learning how to use a screwdriver to take things apart. I opened my C64, wiggled one of these ICs out, breaking the pins in the process. Oh... having to explain this to my parents. They were not happy. I'm pretty sure that was the end of my GEOS days.


Anyone up for a Heathkit-style "learn as you build your own C64" kit?


Retro Recipes did a whole video about this very thing:

https://www.youtube.com/watch?v=Qhdc-jgwqVQ

Studying how the old chips work and recreating them is an excellent way to document and preserve. I'm always happy for projects like these. The eventual availability of Amiga CIAs will save some old hardware, too :)


Wow, I thought this already existed in some form, but it turns out it was actually the PLA that I was thinking of.

>Installing the J-CIA64 requires delicate handling and taking the proper precautions to prevent antistatic discharges.

Also, at least in my non-expert opinion, in most cases you should consider installing a socket whenever replacing chips. You have to solder something new on anyways, may as well make it something that you won't have to redo any time soon. I wound up doing this for every chip I replaced in my own C64, which made debugging it a lot easier. (It was borked when I got it. I'm too young to have owned one new.)


Yes, I put mine in low-profile zif sockets, additionally, I put ESD protection diodes on the joystick ports because that's where you're most likely to touch and fry (including the orignal sid and cias)


What's the advantage of low profile sockets? Sounds convenient, but I just used pretty ordinary DIP sockets. (At least I have a puller to get chips out now though; jimmying with a flathead screwdriver never felt great.)

In terms of space, it feels like there's plenty of room in mine. I have the Perifrantic VIC-II switcher setup as well, which sockets a daughterboard with 2 VIC-IIs into the socket, and that fits surprisingly well. Though, I'd not be surprised if some models had less room to work with.


I wanted ZIF sockets for three reasons things: I want to be able to swap out chips (and their fake replacements) easily to test compatibility and stuff like that. The chance of breaking the pins off of the vintage chips is very real, especially with repeated pulls/pushes. They also put a more constant pressure on the pins, so they _should_ have less of "popping out" the chips, which the wipe-contact type of sockets do a bit sometimes.

The low-profiles I wanted for two reasons, aesthetics, I like how they look, comared to the traditional tall green/cyanish giant monstrocities, and practical: Some of my fake devices are tall, and I risk running out of room in the C64c case (also true for chips below the keyboard), but also, the traditional zif sockets have a much larger footprint than a standard dip socket, and so they actually don't fit on my C64, they collide with decoupling caps AND with each other in one axis (I think it was the PLA and SID that couldn't coexist).

So, I opted for the waaahy more expensive low-profile ones


To me at least, it makes much better sense to go all-in on a MiSTer, rather than gradually frankenstein-ing the build with ARM or FPGA-based chips. There's money to be made trying to maintain these 40+ year old units though. (if the cottage industry surrounding it isn't a clue)


I have an Ultimate64 too, I did this project for philosophical reasons, since everything is new, even the motherboard, it's definitely a new machine, but at the same time, if you look at the electrical activity on the traces, you would conclude it's a c64, and yet, there's no commodore chips on there.. The most commodore thing is the firmware which is on the UV EEPROMs, and even that is slightly different since the original machine used mask roms rather than writable roms. So, it's very much not about "sense" on a practical level (then VICE with a couple of Quickshot competition pro USB sticks makes the most sense)


> there's no commodore chips on there

My Ultimate 64 has a real SID in a socket :-)


A replacement, yes. But is it open hardware? It doesn't seem to be the case.

This is unlike the recently released VIC-II Kawari[0]. That one is OSH proper.

0. http://accentual.com/vicii-kawari/


The guy has worked on a complete chipset replacement for a very long time, I could understand if he would want to earn some money for his efforts before open sourcing it, he's under absolutely no moral obligation to opensource this, but I figure he might some time in the future, if people are nice to him. You know what's also not OSHW ? The FPGAs running it


Who cares if the FPGA is opensource? If the verilog, or vhdl, or whatever was used to program it was available someone could adapt it to other chips.



Good news! The 6526 was always easy to damage through static discharge, by touching or plugging something into the user port.


We're going to have ironically hip webapps in the future, aren't we?

"100% Amiga generated web content"



Which FPGA is it?


The image is too low-res to see the model, but you can see the Lattice logo. This picture[1] is a little better, but still pretty grainy. Best guess is "Lattice ICE5LPxx", where I can't quite make out what the "xx" is. Maybe ICE5LP1K ?

https://retro8bitshop.com/wp-content/uploads/2023/08/F2eV4mB...


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.


I think the point of the J-CIA is to replace a failing CIA in an actual C64. However, that's not what the title of this HN post is about, so I'm not sure what is going on. Regardless, I think making a replacement CIA is very cool, noble even, and I would be happy to buy one if a CIA in my Commodore failed, if it meant having a useable C64 instead of an unrepairable one. But I do agree with you, that building a completely new C64 out of FPGA replacement parts would feel very weird to me. I wouldn't feel like it's the real thing, even if it behaves exactly like one. The big advantage though, if it's a 100% faithful reproduction, would be that it physically behaves like the real deal, meaning you can plug in actual cartridges, build things that connect to the user port, etc, which are things you can't do on an emulator. For now though, I'm just happy mine still works (even though I kinda want to get a C64C instead of my bread bin).


Oh, yes I agree. It is a necessary compromise, much like removing Rifa and electrolyte caps. I would still preserve the original broken IC in the C64's empty internal space, secured somehow, to keep the history intact.


It is the real thing. It does the same thing, just using different technology. It's a fully digital chip, so it doesn't matter if logic is fixed on the die or "fused" on FPGA. It does the same function.

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.


I do not need this condescending lecture about the merits of programmable logic over CPUs and emulation. The difference is not technical or even technological; the actual difference is social. Anything that it is not period-accurate is going to erode the historical value of the artifact, until the point when everything inside is a bunch of fpga's on sockets.


The value of "historical artefacts" is determined by how many specimens remain, and how sought after they are. For whatever reason.

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.


No need in italic font and other passive aggressive stuff. Ask any old hardware enthusiast if they prefer an actual exact silicon level replica of SID or modern fancy shmancy FPGA replacement thing - I guarantee you majority would want the precise replica. Because why people content with these FPGA ugly looking quasi-substitutes, cause there is no actual period-accurate substitutes are available.

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.


That completely depends on your use case.

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.


Emulation is very close to 100% cycle accurate for many, many machines. You would practically not deal with this problem anyway. Now, I may want to tinker with my computer on a board level, making a period-accurate hardware-tweaks for the machine, how exactly I'd accomplish that, if everything is just a big FPGA? Now, having IC'level FPGA substitute for big chips on the original board is a bit better than one big flat fat IC, but it still a different machine and cannot be called C64, as much as a Ford-T is not a Ford-T if you put a modern electric motor to it, even if you tweak it to sound and handle exactly like T does.


For e.g. the SID, where a bad implementation might work but affect the sound, you might have a point, but for the CIA's this a meaningless purity test and sophistry.

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.


No, it is not "sophistry". There is a reason why Apple-I commands these high prices- because it is a piece of history, a slice of technology of the era. If I buy Commodore 64, I won't be buying it for replaying old games, it is completely pointless excercise, I can just buy RPi for that, I will be buying it to have a historical artifact. Now what kind of historical artifact would it be, if the only thing left is the PCB, and everything else are Xilinx IC's designed in 2020s, 40 years later?


If you're buying it as a historical artefact and not to use it, then surely it doesn't matter if it's non-functional either? In that case this isn't for you, and that's fine, but arguing it's not a Commodore 64 any more is sophistry. It's not an "100% original unchanged" Commodore 64, sure. Very few people care about that.


Working historical artifact are way more valuable then non-working. I am surprised so many people do not understand that.


I agree. And it's not just about monetary value. There's just something beautiful about a 40 year old computer still working perfectly. The fact that it's all original is almost a necessity for me to enjoy it to its fullest. I love programming these old machines in assembly language, while at the same time doing my best to understand what is going on inside the machine with each instruction. Replacing original parts with microcontrollers would take away a lot of that pleasure.


If you want to use them, why does it matter if a chip has been replaced? To me, that is what is bizarre. I get the appeal of preserving some. I get the appeal of using some. I don't get the appeal of insisting on purity and retaining only original parts for something you want to actually use, especially when that increasingly means being unable to use these machines because parts are becoming harder to find.

> 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.


If an original part is unavailable, yeah, I'd replace it with a more modern replacement. I prefer that it remains functional more than keeping it 100% original. But I would still first try to find an original part. And I'd feel somewhat disappointed, and the computer would feel a little less appealing to me, if I could only find an FPGA based replacement. I know that's bizarre, and I can't rationally explain it, so I guess I agree with you in a way.


I can get preferring to stick to "real" parts if available, even though it's not something I really care about. I draw arbitrary lines too, I just generally feel it's worth being pragmatic about them if the alternative is losing functionality, which it sounds like you are too.


No it is not bizarre, it is normal and typical feeling in retro community. Check prices on Apple-I or NOS analog components. I'd say it is quite unusual to be indifferent to the period accuracy among those who are interested retro tech.


I think it must be bizarre for why people want original artwork, and do not value replicas. You folks, _bizarrely_ fail to understand what is _historical value _ and what is _period-correct_ _substitute_.

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.


> I think it must be bizarre for why people want original artwork, and do not value replicas. You folks, _bizarrely_ fail to understand what is _historical value _ and what is _period-correct_ _substitute_.

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.


Very funny mix of GenZ and postmodern thinking - from GenZ it is like "I want to signal to everyone (myself including) my connection to history without actually investing into, by buying an insta-history new thing" and from postmodern -"things are what I decide to call them, if I call apple a banana it is a banana" now.

Enjoy your electric Ford-T!


I don't care about signalling anything to anyone. I grew up with a Commodore 64, and to me the value on a Commodore 64 is primarily nostalgia.

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.


Then you should get worked up so much, about not calling it C64. You should be fine then it is not Commodore 64, but just a gimmick that has nostalgic value for you, but not in any way actual Commodore 64 (which it clearly is not).

BTW, good luck reselling your model T as actual model T LOL.


I don't care what you call it, but to me it's still a Commodore 64, and not a gimmick, and I could just as well tell you not to get so worked up over someone else not caring about your purist insistence it is not.

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.


I not being worked up about your opinion, you are entitled to. What I am saying that it should not be advertised as a real thing, as a brand new C64. As simple as that.


precisely my point. I would certainly buy an Apple-1 if it were not as pricey as it is now.


I understand that it is so, I don't see the point of it. It's not an asset that appreciates at a rate sufficient to make it worth it for the value, so it's then down to a purity test. To me they've no appeal as a historical artefact. Their only appeal is for nostalgia, for which being able to actually use them matters far more than purity - if anything, my experience is that nostalgia is best served by imperfect replication that fixes those real aspects that were particularly painful (like easily burning out 6526's...). Especially those we badly wished for at the time (like 6526's more resistant to burnouts...)


There are 2 things you can get from classic computers - a piece of history as you say, but also nostalgia and a return to childhood. I don't think that replaying old games is a pointless exercise. It's just a way to escape from the day-to-day grind and go back to an earlier part of life where things were just a lot easier. So I hear what you want from computers, but there is a lot more to retrocomputing than just hardware preservation.


Totally agree with you; my point is that for replaying old games, RPi is well enough. No point in making what is esentially a hardware emulator and calling it "the real thing".


Ah, I see. On that, there are different degrees of "realness". Aside from historical preservation, there are enthusiasts (I might be one of them :) ) who want the most realistic possible retro experience given the constraints of ageing hardware.

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.


The problem is that FPGA's are not 100% hardware replicas of the chips. The only way to be close to tru experience is to use newly made silicon, but made according to the blueprints from 1970s. For example 6502s sold today are of this type; also 74AC/HC/LS chips.


These are for the most part digital chips. If you make a cycle accurate replacement, they're close enough in that they for most users won't change the output. E.g. here's an in-progress cycle accurate 6510/8500 replacement, that is if anything more compatible than some of the alternative "period" licensed 6502/6510/8500 designs, where support for the undocumented instructions vary:

https://1nt3r.net/j-cpu/

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.


They are not hardware replicas (as in "the same circuits"), but as far as the pin voltages are concerned, they can behave exactly like the original chips. And when I say "exactly", I don't mean "pretty much the same", I mean the same. That's the beauty of the digital world, it's absolutely possible to fully and perfectly emulate digital circuits.

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.


It is not the point that replica behaves "perfectly same", the issue is that they are not period accurate. Even it is a perfectly

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.


as long as you don't have to load games using the datasette. haha.


You pay for some combination of:

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).


Your assumption is unjustified TBH, because HN comment section is not representative of retro community. Now I also cannot understand how something can feel same as old historic device - this is not true even for differen gens of the same hardware. Say Apple-IIe feel substantially different from IIc and deeifferent generations of Sony PS 1 are also feel different.

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 retro community is what drives the demand for these replacements.


Because there is no modern period-accvurate replicas. There is a reason NOS components command high prices.


That might be an argument if the only market was for projects like the linked one, which provide drop in replacement for period-accurate replicas, but the market is also full of full FPGA reimplementations and machines that adds all kinds of additional features, which shows there's a substantial portion of the retro community who don't care even about whether the result provides accurate reproductions.


This is not a market for retro, it is a market for replicas, an entirely different one. Still a replica is a replica, and should not be advertised as a brand new original machine, which the original title (before edit) was about.


Last time I wanted to fiddle with a C64, I just went and flashed bmc64 (https://github.com/randyrossi/bmc64) to an SD card. Even an original Raspberry Pi 1 does a decent job of emulating it.


Exactly mt point, no point in buying a bunch of Xilinx FPGA's and calling it Commodore 64.


Once configured, a FPGA is the hardware that's configured into it. It's cheaper than an ASIC, unless you make a shitton of them.

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.


The 6526 is infrastructure--it's a timer, clock, and I/O chip and doesn't really have anything to do with the interactive look and feel of the system. So an FPGA here doesn't harm the C64's soul one bit, if it works exactly like the original.

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. :)


This is a silly argument.

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.


Well that’s just like your opinion man.

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.


FPGA is in absolutely no way more faithful, which FPGA implementation has 100% compatibility with all internal and external interfaces ?


I wouldn't equal the possibility of taking a C64 with one or two broken chips and replacing them with a cheaper, more reliable modern equivalent to tossing the whole machine away and going 100% emulation.


Neither would I, but this is not what the title says.


I don't know that for a parallel/serial/rtc chip you would really see any difference. I can see your point for some of the harder to emulate parts like the SID.


the Audiophile argument


100% agree




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