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J-CIA64 – Modern spare part for Commodore 64, Commodore 128, SX-64
- dusted 3y agoI 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/ http://dusted.dk/pages/c64/MaxFake64/
- wkjagt 3y agoVery 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.
- dusted 3y agoI'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.
- wkjagt 3y agoHow 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.
- dusted 3y agoI 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.
- wkjagt 3y agoHmm maybe I'll put a C64C on my list of "things to buy if they happen to pop up at a reasonable price".
- SomeoneFromCA 3y agoNo, 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.
- bullen 3y ago100% agree
- nemo8551 3y agoWell 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.
- vidarh 3y agoFor 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.
- SomeoneFromCA 3y agoNo, 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?
- vidarh 3y ago
- twarge 3y agoWhich FPGA is it?
- tyingq 3y agoThe 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/F2eV4mBaAA0lWl0-2.jpeg https://retro8bitshop.com/wp-content/uploads/2023/08/F2eV4mB...
- codeflo 3y agoWhat 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?
- vidarh 3y agoDigital 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 https://retrocomp.cz/produkt?id=2
- fluoridation 3y agoThey were accurate, just not precise. ;)
- wkat4242 3y agoIt'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.
- dusted 3y agoI'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 ^_^
- nxobject 3y agoAnyone up for a Heathkit-style "learn as you build your own C64" kit?
- lmpdev 3y agoI 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
- unwind 3y agoYou 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/ https://www.c64psu.com/
- dusted 3y agoYou 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 ;)
- HPsquared 3y agoCan't you just use some filtering caps? (spoken as a non-EE)
- lmpdev 3y agoEdit: Do NOT use LM7805s in parallel, they don't load balance evenly
- jwr 3y agoThe 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 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.
- snvzz 3y agoA 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/ http://accentual.com/vicii-kawari/
- dusted 3y agoThe 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
- LordLotherak 3y agoTo 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)
- dusted 3y agoI 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)
- jwr 3y ago> there's no commodore chips on there My Ultimate 64 has a real SID in a socket :-)
- jchw 3y agoWow, 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.)
- dusted 3y agoYes, 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)
- jchw 3y agoWhat'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.
- dusted 3y agoI 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
- the_af 3y agoTangentially 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!
- dusted 3y agoA 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 ;) )
- icedchai 3y agoI like both. The software is so much more convenient with emulation, but seeing the real hardware feels like it takes you back in time...
- the_af 3y agoTheC64 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.
- the_af 3y agoI 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 :)
- Damogran6 3y agoWe're going to have ironically hip webapps in the future, aren't we? "100% Amiga generated web content"
- stuff4ben 3y agoI 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.
- fallat 3y agoNot just nostalgia. I want to experience what the first personal computers were like. I think there's a lot of value there!
- bobboies 3y agoI 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.
- myself248 3y agoI 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.
- johnklos 3y agoRetro Recipes did a whole video about this very thing: https://www.youtube.com/watch?v=Qhdc-jgwqVQ 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 :)
- jwr 3y agoGood news! The 6526 was always easy to damage through static discharge, by touching or plugging something into the user port.
- semireg 3y agoAm 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.
- rasz 3y agowonder if relate to bwacks https://github.com/bwack/VHDL6526 https://github.com/bwack/VHDL6526 https://www.youtube.com/watch?v=FLxncR7Ru4Y https://www.youtube.com/watch?v=FLxncR7Ru4Y