As the headline say’s, is there any VIC-II video chip replica out there in the wild, or any project that are trying to recreate/replicate that chip? I am thinking about something that are a drop in replacement of the original VIC-II chip that are found in the C64. The SID have been recreated in FPGA, and so have nearly all other chips (in various forms), that are used in that computer. So why no VIC-II, or have I looked at the wrong places?
I have no doubt there are FPGA models, and hope some of them are open source, but making a drop-in chip is quite a challenge (5V interface, small form factor, surface mount devices.) If it hasn’t happened, I suppose it’s a lack of perceived demand - whereas there’s a clear demand for SID chips, for new projects or as replacements - or an oversupply, in the form of recycled chips from secondhand C64s. It’s almost a disadvantage that so many C64s were made!
It feels like it doesn’t help, in searching, that the chip came in six different part numbers (at least):
The VIC-II (Video Interface Chip II), specifically known as the MOS Technology 6567/8562/8564 (NTSC versions), 6569/8565/8566 (PAL)
Another obstacle to putting a product out into the C64 fanbase is that, on that platform, all sorts of side-effects are important to some people (and some software) so if you don’t aim for exact cycle-and-bug compatibility you might get negative attention. The perfect being the enemy of the good.
I just thought that with nearly all parts (excpet the keycaps them self and the VIC-II chip it self) being readily avaliable as newly produced aftermarket parts. Yes, you can actually build a brand new C64 with factory new parts, except those two parts. Well… Then I thought that it is really strange that there is no VIC-II chip, reborn and ready. The talk in the Commodore community, are as you said, mostly centered around that fact you brought up. That there are minor differences in each model and revisions of the VIC-II. Yet for gaming and programming, possibly other generic operations. Then you actually do not notice those minor differences. You are well off and it does not matter wether you are using an 6569 Rev. 5 or 6569 Rev. 3 or 8565 Rev. 2. Sure there are subtle differences, like the contrast between certain colours on an 6569 Rev. 1 are horrible. And that is still only in certain games, like the main menu in Winther games. They used this really delicate neon light blue colour as a background colour and the same nuance of green as the text colour. And on the 6569, the contrast between those two colours, makes the text almost disapear. And trying to read it, gives you headache. Using a good CRT monitor, still does not solve that issue. Yes. The old 6569 with gold top are just garbage. Here it is way better to get the system and RF modulator recapped, and then swap the VIC-II out for eighter an 6569 Rev. 5 or build an adaptor that makes the system able to use an 8565 Rev. 2. Or simply just buy a C64 Model-C and install the Lumafix64.
Using the C64-C poses different issues with the VIC-II video signal. They solved the contrast issue in general. Yet there are still minor issues. Like the C64-C outputs some faint jailbar-lines or vertical spaghetti lines if you like. These are of no real concern, if you have a perfectly working old CRT monitor, that were build specifically for the C64. Yet if you find a way to have the machine working well on an LCD monitor (TV), then you will see those lines. They are still visible on an old CRT television. Yet you really have to look for them if you are using composit cable. They are more visible, using Scart. Another small tip is, that if you are using composit, then the absolute best C64 cable for the C64-C is actually the 5-Pin-DIN to Composit, made and sold by retrocomputer-shack in the UK. Anyway… Installing the Lumafix on the C64-C, makes the absolute best image quality. And between C64-C models, there are still differences to look after. The absolute best C64 machine. Is the first of the three C64-C models that were released. It’s video output stands out as the absolute best, and the machine still have the old SID chip. The special thing about this C64 machine, is that the systemboard is a “longboard” (the one used in the breadbin machine). If you can get your hands on that machine, then I think that the board revision is 250466 or something like that. 250407 and 250425 are still the old breadbin.
Yet it could get worse. The PLA chip as an example, have been reported to self destruct over time. The designer of the chip, have reported that it was made in a way, that it automatically degrades over time. And the chip is extremely prone to fail, due to heat exposure. Luckily, there are like the first 5 different microcontroller and fpga based versions of that. Some with and some without the clock chip.
Speaking of the different variatnts. There are both NTSC and PAL versions of the VIC-II. That leaves basically 3 models to explain. The first is the old VIC-II. It uses both 5 and 12 volt on Pin-13 and Pin-40 of the chip (13 is 12volt and 40 is 5volt). The second chip is the new VIC-II that uses 5 volt on both Pin13 and Pin40. And finally there are the Vic-II that was used in the C128 machine. The C128-Model is one that I have no direct knowledge on, other than is has some slight upgrades, like 2(4?) more pins on the chip. Possibly more internal upgrades to the core. Well… I can’t remember that specifically, as I have not dived into that chip at all. You can call it VIC-II version 2,5 if you like.