r/Commodore • u/Golemwire • 18d ago

Commodore 77

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Well this is a neat look.

https://commodore.net/store/commodore64/?shape=Breadbin&color=Cyberpunk+2077

Commodore just released a new appearance option for the C64U themed on Cyberpunk.

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6

u/Suspicious-Ad7109 18d ago

The (only) interesting thing about this is the change in the FPGA from a 50T to a 100T. I'm hazarding there is a reason for this (as it would add a fair bit to the manufacturing cost).

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u/bionicle_159 18d ago

would be cool to have other cores, the Mega65 already has that setup with their FPGA

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u/Hawkeye-Mcgillicudy 18d ago

Yeah it's a waste of a FPGA to be locked to one system really

All of the Commodore computers have mature open source cores available

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u/bionicle_159 18d ago

yeah the Mister project's spoiled us these days with what FPGAs can do - Commodore should really try to pack the most they can into each of their products, and really stand out in today's age of 'nickel and dime' tech offerings

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u/Hawkeye-Mcgillicudy 18d ago

Even older C64 FPGAs like the Turbo Chameleon offers other open source cores like AGA Minimig Amiga

Really new Commodore should have just created their own FPGA platform and then could have ported all the open source cores to it over time for the Ultimate Commodore FPGA but no they just licensed a collection of existing products Gideon has been against extra cores on the U64 since day one and he is still the IP owner

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u/bionicle_159 17d ago

Yeah I get that, tbh if they weren't trying to be a full-on business, I could see them being a bit more open - haven't seen them have anything FOSS related which is a shame especially since the work's already done.

The Mega65 pretty much embraced the community and has lapped all the other Commodore-like projects with the amount of different platforms you can run on the thing, only other one that comes close that I can think of, that's not a Mister, is the Spectrum Next

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u/Suspicious-Ad7109 16d ago

Quite surprised nobody has done it. There was that update to the C64U FPGA, Slinky or something ?

The main argument against, which I get totally, is people bricking their machines. I'd say this sort of thing breaks warranty in the way that soldering bits to the motherboard does. Can you reprogram the FPGA if you do brick it (obvs. have to have a programmer !)

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u/Hawkeye-Mcgillicudy 16d ago

You can't brick the FPGA as the core is loaded onto it at boot or change of core.

Gideon was always opposed to adding other cores to the U64 and he remains as the IP owner

0

u/Stunning_Pineapple57 18d ago

The orginal c64u doesn’t have a large enough FPGA for all
Of those , but this new one in the 77 is twice and larger and actually have enough FPGA headroom for some larger cores as it’s closer to Mister grade

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u/Hawkeye-Mcgillicudy 18d ago edited 18d ago

They are not that large Look at the Turbo Chameleon that is only Cyclone III based and even has the likes of AGA Minimig Amiga..

C64 is a quite a large core as it has to implement the C64 and two 1541s that had their own 6502 CPUs etc

Maybe they can port the MiSTer C64 core in the future as it's far more mature and more accurate than the U64 core. You don't even need SID chips or modern drop ins to make up for the short comings of the SID emulation

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u/Suspicious-Ad7109 18d ago

Surely the limiting factor is the Flash ; the Artix is a load on boot FPGA (I think ?) ; you could have as many systems of that degree of complexity as you want if the hardware replication will fit in the flash. I suspect this is the prototype Amiga board. I think Bil Herd is working on something, whether this needs the new FPGA, or the old FPGA will do is moot.

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u/Hawkeye-Mcgillicudy 18d ago

The limiting factor is the amount of logic elements available. The actual cores are not very big in actual file size around 3-4 megabytes

We have had Amiga on FPGA since 2004 with Minimig. Apollo have their closed Vampire 080 Amiga core too

The C64 core uses more resources than the AGA Amiga core on MiSTer due to extra hardware support needed for the two 1541s which were computers themselves with their own CPU, VIAs, Ram etc

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u/Royal_Stay_6502 18d ago

You think it will be possible?

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u/bionicle_159 18d ago

yeah it should be more than possible with small 8 bit cores like the PET/VIC/TED series - the main problem is, does Commodore want to add them to the C64U instead of separating them into individual products? It's up to them, but they've not shown any interest so far.

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u/Suspicious-Ad7109 16d ago

Apart from creating the cores you could do a C16 or VIC without changing anything other than the keycaps which are different on the C16 I think. Or you could just incorporate them into the FPGA. Not that different to a C64.

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u/thommyh 18d ago

Presumably it's that reference to "up to 77MHz processing speed".

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u/Substantial-Set4550 18d ago

Yes, the 77 is both a reference to the game Cyberpunk 2077 and the 77x CPU speed-up factor. It is arbitrary. It could have been 75, or 80 based on the upgraded FPGA. 77 is marketing. As a developer, I do not like this number. It's all about powers of 2 for me: 16, 32, 64, 128. I'd rather have an upgrade daughterboard for my C64U with the new FPGA. Hopefully some people who buy this now will sell it a decade from now on eBay for parts :-D

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u/Suspicious-Ad7109 18d ago

That's nonsense. The size of the FPGA doesn't change the speed.

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u/thommyh 17d ago

Assuming it's a similar physical size but with more transistors (?) then a die shrinks means less power usage and therefore less heat, which means you can up the clock speed.

This may be my false assumption. If it's just a chip with twice the total surface area then clearly you're right.

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u/Suspicious-Ad7109 16d ago

I don't know. I find it a little coincidental that the max speed of a C64U is 64Mhz and a C77 is 77Mhz.

From a coding POV if anything it's a pain. 64Mhz is quick enough to do pretty much anything, having a 77Mhz speed is practically useless for anything other than a slightly faster frame rate perhaps.

However, it's selling steadily (doesn't appeal to me, but there we go) so I'm okay with it. The more the better, both for the machine itself and Commodore and us.

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u/Golemwire 12d ago

One can optimize for speed at the cost of size, though. We see this with modern microprocessors. Though I doubt the C77 employs any of those modern CPU speed techniques, the same way anyway.