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Speeding up a Color Classic - Without mystic or Takky

PhidoMac

Member
his, but it would NOT be cheap. On a level of a 575 board if not more, I reckon.
still, swapping a logic board in a CC is easier that removing a PDS accelerator - in both cases the board has to be extracted from the machine.....

Well I guess if I get a full 68040 for my LC630 I guess I would have a spare 680LC40 which could go into such a device. But there is quite a bit of work on that 68040 board. A 68040 is still going to run slow sucking down from a 16Mhz, 16bit bus.

However, its getting much harder to get 575 boards in Australia, and buying from the EU and US is a waste of time, several times I paid buy now prices or won an auction, then the sellers just cancelled the sale and relisted rather than trying to post the item internationally or deal with an international sale, annoying a few days later. The annoying thing about that is other opportunities are lost or additional equipment is acquired for something you no longer have. I don't see this getting any better soon, and for some reason my currency has taken a huge dive, items are now twice as expensive, and post covid, it seems no prices have fallen either.

The other issue with accelerators is you loose the single slot of expansion. So no ethernet, no external video, or no DOS cards (on machines that can support them). I guess I could use a wifi modem on the serial port.

In the PC world there are some accelerators that disable the CPU, or go in and replace the CPU thus, don't harm expansion. I guess I am also interested in learning more about accelerators, and sticking a mystic motherboard, after half a dozen failed attempts to get one, I am not sure will fill my satisfaction hole.

Swapping a 20mhz or 25Mhz crystal would be an easy try and would still make an accelerator faster. A spicey-clock that actually outputted 32-50 Mhz would be ideal for non-040 macs
 

ObeyDaleks

Well-known member
Hmm i just checked and 575s are indeed pretty crazy on eBay.

Although, I thought I saw some full mystic builds on Buyee recently for pretty cheap, maybe $300 ish range?

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.

Edit: I just checked and I do see a full mystic listed on Buyee for a (imho) fair price.
 

DrGonzo

Active member
Yeah, I'd love to try to build up an 040 board with RAM/Ethernet as well since then the CPU would have fast access to memory (and a lot more of it) and would have network (obviously). I don't think the cost would be to outrageous to add the network chip/jack and the extra RAM. The Tokamac from Bolle probably will cost around $100-ish in parts. Maybe $150 top end to add RAM/network? Just need someone with the skills to replicate the aforementioned 040/RAM/network board which unfortunately, at least today, is not me. :(

~Dr. G
 

PhidoMac

Member
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.
 

badferday

Active member
I have a colour classic. I am spending some time restoring it, recapping it and the analog board, VGA mod, etc. I know at the end of it, I will have a very slow Mac.
But I have been having deep thoughts about how to make it faster.

The days of finding lazy 575 or 550's for cheap are long gone, and people now know these are worth something. While in big markets like the US it is possible to find them, shipping etc adds significantly to the cost, and fundamentally, you are changing the board. At some point its no longer a color classic, but a home for another machines board, which by the time you do the takky mod, you might as well put a whole new machine in there like a Rasberry Pi as you are just using the CRT from the original computer and molesting the insides in a non reversable way.

So I wonder, if we are keeping the modifications to the original motherboard what options are there:

  • It is generally listed as these Macs are not overclockable, yet the LCII they are based off are. Looking at the mobo its got a 31.3344Mhz clock crystal that I assume is clock divided to 15.6 Mhz. Perhaps a crystal change or a clock generator would be useful here. 16Mhz was quite slow for the vintage of this computer and the RAM and VRAM should be able to handle a bit of clocking looking as it is as 70ns DRAM and 80ns VRAM . I would imagine a 40Mhz, 50 or 66Mhz crystal could be at least tried. I believe the graphics portion is downclocked from the base clock on the LCII there is a seperate clock generator, and it has been able to be overclocked seperately.
  • Now I know that Mac Effect has a clone of the original MicroMac Thunder 68030 32Mhz accelerator. A seemingly simple and highly compatible accelerator. After I finish restoring my colour classic, I am considering buying it, perhaps after experiments in overclocking. Has anyone run one of these boards in an overclocked LC/LCII/Color classic? If shooting for something like 20Mhz clock, then I assume these would clock double that AFAIK they don't seem to have a crystal soldered onto them? A 40Mhz 68030 would seem possible with a 50Mhz being perhaps worthy of a try with a heatsink attached? Are these CPU's socketed?
Just joined, so a little late to reply, but this YouTuber is amazing. He has a whole series on working with the original CC hardware to get the most out of your computer. Love his channel!


This is the playlist on that topic:


Edit: The playlist does have some Mystic stuff, but also has a lot of stuff you can do to work with the original Colour Classic/CCII hardware. My bad.

- Katrina
 
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JC8080

Well-known member
I have a Sonnet Presto '040 accelerator in my CC, here is a link to my post which includes benchmarks. It benchmarks halfway between a stock CV and a Mystic, and about the same as a IIfx. It makes the machine very useable and no longer feels slow.

Mine is not the Presto Plus with the on board RAM, so it is limited to 10mb of RAM on the narrow data bus. That doesn't affect anything I would want to do with the machine, but might impact others.
 
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