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Thoughts on retaining the 65C02 all the way to phase 3?
Posted: Sun Jul 16, 2023 3:23 pm
by BlahDehBlah
Because phase 3 aims to reduce the cost of the board as much as possible, all mention of this phase (that I've heard of, that is) suggests lumping everything together into a custom FPGA or "system on a chip." This, indeed, would cut the cost tremendously but it does lose a little bit of the magic. To me, a genuine 6502 is the bare minimum. Putting everything else on an FPGA to save costs is fine by me as long as I could, hypothetically, hook an oscilloscope up to the data lines and see the 1s and 0s flow between the CPU to the black box that handles everything else. This would be as far as one could simplify a board before it feels identical to just emulating it entirely on an actual Raspberry Pi (which I think a $10 Pi Zero could do [if you could get your hands on one]). However, the question then arises how feasible would a design that retains a discrete 65C02 alongside the FPGA be? Would it make phase 3 too similar to phase 2 and therefore make one of those redundant? Would keeping a genuine 6502 inflate price too much and blow the price goal for phase 3 out of the water? What do y'all think?
Re: Thoughts on retaining the 65C02 all the way to phase 3?
Posted: Mon Jul 17, 2023 2:54 am
by Daedalus
Where the wheel hits the road is "Emulation vs. Hardware."
Emulation is where you're using a way more powerful CPU to simulate the CPU of the target system.
Hardware is where the target CPU's SA (System Architecture) is running directly on silicon OR being run by more powerful, general purpose silicon that's been programmed with that CPU's SA. (A.K.A. an FPGA.)
FPGAs are the future for the hobby retro computing market. Direct silicon CPUs only have a future at the leading edge... just look at the microcontroller market, there are a dozen variants of each one coming out every year, with each one replacing one only a few months old. This is fine if you're a huge player buying a hundred thousand parts at a time... you can retool for each variant or better yet, be big enough to actually DRIVE the variants in your direction to reduce total system cost.
But we, as solo hobbyists or members of a small hobby group, simply can't do that.
We have to buy our stuff OFF THE SHELF.
The reality is that discreet retro CPUs are freakin' dinosaurs. The only way they can communicate with other components is through equally dinosaur level interface chips that are ludicrously expensive in respect to their actual functionality.
The only thing you can buy off the shelf and then configure to be like a retro CPU or an interface to a retro CPU or a system that can do both is an FPGA.
Re: Thoughts on retaining the 65C02 all the way to phase 3?
Posted: Mon Jul 17, 2023 4:06 pm
by Wavicle
The biggest problem I see here is that the W65C02S is kind of expensive.
Emulating an X16 is difficult even for fairly modern machines mainly because both VERA and YM2151 are computationally expensive to emulate with reasonable accuracy.
Re: Thoughts on retaining the 65C02 all the way to phase 3?
Posted: Mon Aug 07, 2023 12:35 am
by The 8-Bit Guy
Phase 3 is going to be all about cost reduction. If having a real 6502 is important to you, I'd recommend just sticking with a phase 1 or 2 board, which should have a real one. Those boards aren't being replaced by the later one. They aren't going away.
Re: Thoughts on retaining the 65C02 all the way to phase 3?
Posted: Mon Nov 06, 2023 9:07 pm
by retro_hamster
I think that the lack of real hardware magic of Phase 1 and 2 will make the Phase 3 irrelevant for those of us who gets goose bumps thinking about a proper real 8-bit machine with a beating 6502-like heart. And on the other hand, Phase 3 will be interested in those who dig the SOFTWARE experience of the CX16. They come for the games and lower cost, and while they want a real box, they aren't getting all hot and bothered about how their bits and bytes are transported around inside the system.
Another thing that I prefer with the ASIC approach is that the scope is narrow and fixed. IF you FPGA the system, why stop at one specific? There is no reason to limit yourself. It is like the MEGA65 project. C64 in an Amiga like encasing but the content is a FPGA that suddenly runs GameBoy Colour as well as a 40 MHz 6502. Before you know it, RetroArch is installed as it can do everything the FPGA software will allow. This is kind of saying "Let us play we can only walk" when you have a car, a bicycle and Uber.
Btw I only found out about this a few weeks ago. Well, I did see it earlier, maybe last year, and didn't pay too much attention to it. Probably because of Mega65. But the thought of it being a "proper" home micro makes me excited.