Another option might be to find a TransWarp 4300 card. I don’t know what kind of magic they use, but the TransWarp cards provide a shockingly huge performance boost (like IIfx speeds) - maybe it’s their drivers combined with clever use of the onboard cache. I saw a couple sell on eBay recently for somewhere around $200. Pretty sure they will work in a CC.
Cache will make a huge difference.
[rant on accelerators and memory buses]
That 16bit 16mhz memory is really going to choke performance no matter what you socket into to it.
The 33mhz 68030 main advantages is instructions that don't need to access the main memory happen at double the speed. But this only makes up about half the instructions. Even with a 68040 at 40Mhz, any loading from memory or putting things back into memory happen at the 16Mhz, 16bit bus speeds. Unless you have on board cache, or/and on board memory. But at that point you are effectively plugging in a motherboard into the other motherboard. Which means huge cost, huge complexity, huge development time, huge board and very hard to clone. Many of the accelerators took a long time to come out after the 68040 was on sale. The more complicated you make it, the more you can have compatibility issues as well. The big advantage of a 040 accelerator was Floating point was basically unaffected, as it was so slow compared to ALU and not heavily memory dependent.
The 68040 already has reasonable caches on chip 4kb + 4 kb. Im not sure if it is worth it these days to have a separate cache controller.
With PC's 286 and 386's can be upgraded with a ti486sxlc which has a clock doubler AND 8kb of L1 cache and these were available for the 16bit bus of the 286 and 386. Even then, they aren't the same as a full 32bit 33mhz system, but they get it fast enough to play Wolf3d and serria games aren't just a slide show. Intel also made a 8Kb self contained L2 cache chip with SRAM and cache controller inside. Even then, PC accelerators go for crazy money. A 286 or 386 to 486 accelerator can often sell for $300-$500 USD. A IBM Bluelightening can go for more than that. Which is a bit crazy given you can pick up a Pentium mainboard for $20 or even a whole Pentium PC for $50.
A simple clock doubling and 68040 adapting accelerator would probably be the most efficient use of price and parts. But again it still takes away the one PDS you have. I don't know if there is a cheap single chip cache controller for 68000's we can use, and cache controllers need to be setup to manage DMA and interrupts etc.
Things like the applesqueezer use FPGA to basically add a CPU upgrade with on board memory and basically a whole chipset of capability etc. The Ultimate 64 cartridge's has Wifi, 16Mb ram, Sd disk storage, a memory blitter function, and costs 150 euro. The applesqueezer is a 25mhz upgrade for IIGS's that cost 300 euro, but its cheap if you consider buying a slower IIGS accelerator, a ram expander, networking, storage etc separately.
If you could clock the Colour Classic to 20Mhz, and throw either a cheap 68030 clock doubler or a 68040 on board for around $150, that would kill the mystic swapping craze dead, IMO.
Because do you really need a full 32bit 68040 in your CC? What game is suddenly playable at 040?. I wouldn't say Doom, Duke3d, Marathon are playable on any 68040. Wolf3d is not much chop either. We all have machines *way* more appropriate for those type of games and tbh the Mac isn't famous for being the machine to run those type of games. And its not impressive even if you did a complete tackky mod an stuck a 400Mhz G3 in there. It doesn't blow peoples minds like a C64 playing doom with a sid music soundtrack at 100+FPS, a machine that in no way should even be able to do that, but does it using the originals video circuitry and sound chips and keyboard/joystick.
[rant off]
At 68040 is nice, but is a must have in for $500 usd into a colour classic?
I've chatted to Mazz. I will be assembling a 030 accelerator. See how I go.
I want to evolve the design. Either with a cache chip or to a bare 040. Not sure if I am clever enough to do that. But I want to try, worse case I end up with just a regular accelerator and I leave it at that.
I also want to create a 286->ti486slc2 adapter for my 10Mhz PS/2 50z with MCA bus, which has the many of the same issues, a slow 10Mhz bus on a 16bit bus, a slow 286, and without a memory expander (costing $100usd+) a 2Mb ram limit. But its in a unique quriky case, and died, famously with the brand going in a very different direction, while still having some success and a legacy (PS/2 ports, PS/2 SIMMS, open standard expansion). From what I can see the concepts are very similar, maybe some ideas from PC accelerators can come to macs and some mac ideas to pc accelerators.
Both of these projects are more about learning about these ancient machines and the magic there in. Sometimes you can actually add more magic with a modern repro or modern addition. Particularly if it highlights the originals strengths and unlocks talents in a new way.
I guess I am searching for that x-factor modern addition to the colour classic/LCII that adds to the original flavor.