CC & 575 upgrade question

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Joined: May 9 2015
Posts: 62

I hope someone can help me. Maybe you can post a link to a web site for me to read? Many of the links I have been trying are now dead. Here is the deal....

I made a great score and found a Color Classic (now my second) at the Goodwill for $11.95. After a new battery and a acetone wash it came to life. Around the same time I received a free Performa 575 and the only thing wrong with it was a bad PRAM battery.

I had read a little about a 575 upgrade to a CC so I thought I would try it. Yes, I know it is a modest upgrade, but that is OK with me. I am looking for 640 X 480. My first CC has a CC II logic board in it and I am happy with the speed. I sent the Performa 575 logic board and the 575 analog board out to be re caped. After the re cap, I installed them back in the Performa and it works great. Now I want to put 575 analog board and 575 logic board in my CC.

I took my re cap'ed 575 analog board over to my buddies house. He is a wood worker and has a 2 thousand dollar band saw with an extremely fine blade. After careful measuring we were able to cut down the 575 analog board to 9 and 5/16th's of a inch wide. It will just sit on top of the railing (after it is cut down a tad) where the CC analog board would go.

I am confused by a few things...

Isn't the 575 logic board a slide in replacement for the CC logic board? I know I have a little more cutting to do on my 2nd CC to make the analog board fit.

I looked at this FAQ:

http://www.fenestrated.net/~macman/CC575/

But I did not understand it all. I believe in the above FAQ it is talking about a Takky mod to a CC logic board. I want to use a Performa 575 logic board and a 575 analog board.

Maybe the 575 logic board will not fit the CC?

If someone could point me to a FAQ for more information I would appreciated it.

I am sure I am not the only one here who is trying to install a 575 analog board in a CC.

Any tips appreciated.

Thanks

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Dr. Webster's picture
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Joined: Dec 19 2003
Posts: 1687
Re: CC & 575 upgrade question

The 575 board isn't a perfect slide-in replacement. Depending on which OS version you plan to use, you need to either install a specific system enabler, or perform a hardware modification. Here's the specifics:

http://www.applefritter.com/powercolorclassic/stuartbell/compendm

Things get a bit simpler if you want to perform the 640x480 mod.

The link you provided is for doing the Takky mod, which is the installation of a PowerPC-based board. Those are *not* slide-in replacements, as such boards are deeper than CC/550/575 boards. Using a 575 board in a CC is known as the "Mystic" upgrade. Even back when these mods were popular, I didn't hear of anyone modding a 575 analog board -- everyone just did the resolution mod of their choice to the CC's analog board. I think the reason why is because of something noted in your link:

Quote:

This modification will not work with a stock or "Mystic" upgraded Color Classic without modification of the monitor sense line coding, which I will not discuss.

So it sounds like if you wish to proceed with the analog board swap, you'll need to rewire the wiring harness between it and the logic board.

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Applefritter Admin

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Joined: May 9 2015
Posts: 62
Re: CC & 575 upgrade question

Thank you Doc. You have saved my bacon more then once. I appreciate it.

When you are talking about a 575 board, I am not sure if you are talking about the 575 analog board or the 575 logic board.

I will read the link you posted.

I know about the Takky and the other mod (the VGA mod?) to give one 640 X 480. But I do not like either mod. I think they push hardware beyond the designed parameters. I would like to give my CC 640 X 480 with out pushing the hardware.

I know that I need enablers (I plan on installing 7.6.1 on the 575 CC).

My very meager understanding of monitor sense line coding is that you can do it two ways -

1) re wire the wiring harness. I don't want to do that in case I want to roll back the CC to maybe another CCII board.

2) do some line coding. I found a web site once that talked about this, but I can't find it again.

I have the CC taken apart. I can not get the 575 analog board to slide in the slot of the CC analog board. However, if I cut down the top of the slide in, the 575 analog board will sit on top of the CC analog board slide in. I had to remove the metal shield next to the plug in (in the 575 analog board) and cut it slightly and fold it, then re install it, and then the 575 analog fits. I also need to do more cutting on the inside plastic near when the plug is for the analog board so I can get the buttons to line up. Looks like it is not a big job - I have a dremel tool and many bits.

I am a newbie at this, so I suspect someone else has already thought about it and done it. But I can't find a link to a page that talks about it. Most links are now dead. But I might have to hunt and peck away at many links until I can gather all the info I need.

I think the 575 analog board and the 575 logic board would make a good match and produce 640 X 480 with out pushing old hardware out of it's designed operating range.

I am off to read the link you posted. If anything else comes to mind drop me a line please. And if you think what I am doing is nuts, please let me know that as well. I very well could be going off the rails doing this mod.

I will try to document this mod and some time in the future (if it works) post a web page with all the details.

Thanks again for your help. I hope I am not crazy trying to do this.

jack

Dr. Webster's picture
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Joined: Dec 19 2003
Posts: 1687
Re: CC & 575 upgrade question

Well, what I think it really comes down to is this: How "undo-able" do you want the mod to be, and how much risk are you willing to accept?

1. If you want to keep the CC 100% stock, simply slide in a 575 logic board, install the appropriate enabler, and call it a day. You can revert to the original CC logic board at any time, and there's no risk as there's no modification needed to the rest of the CC. The downside is that you're stuck at 512x384. This is known as the Mystic mod.

2. If you want 640x480 and a modest bump in speed, do the Mystic mod and perform the resolution mod of your choice to the CC's original analog board. No edge connector rewiring is necessary, since you'd be using the original one with the original analog board. You could revert to the CC's original analog board, but the mod to the analog board would likely be permanent. There is some risk of causing the original analog board to fail prematurely, but there's nothing more than anecdotal data about failures so it's hard to say how likely it actually would be.

3. If you want minimum risk to the original components but higher resolution and faster speed, continue as you've planned by replacing the analog board with one from a 575, and install a 575 logic board as well. As you've found, the original edge connector isn't compatible with this, so you'd need to either 1) rewire it or 2) replace it with the one from the 575. Both of these options would involve permanent modification to the CC and make it difficult if not impossible to revert back to stock.

4. Or you could go all the way and do a full Takky mod. This involves keeping the original CC analog board (and doing a resolution mod to it), rewiring the edge connector, permanently modifying the CC's inner chassis, and installing a PowerPC-based logic board. Definitely not undoable. You could swap in the 575 analog board if you prefer, as was shown in the link you provided. You get the best performance this way, but at the greatest risk.

No, you're not crazy. Others have done all of these before; I did a Takky mod over 15 years ago when I managed to obtain two Color Classics. I ended up selling the Takky and still have the other, stock CC (which will remain that way).

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Joined: May 9 2015
Posts: 62
Re: CC & 575 upgrade question

Doc....

Thank you for making this clear to me. I believe I have a better understading of it all now. To tell you the truth, I am not shure what I want to do. I am thinking about option #2 and #3 at the moment. But I will have to read up on it so I fully under stand it all. I do wish to have 640 X 480. And a modest speed improvement would be nice. I do not like cutting up my Color Classic. But, I think the 575 analong board and the 575 logic board are a good solid match. I think I read about a CC case cut up mod to do this. But I hate to cut up my CC case.

I need to think more about it before I decide. Thank you again for all of your help.

jack

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Joined: Jun 23 2014
Posts: 1
Re: CC & 575 upgrade question

re dead links, have you tried archive.org's wayback machine?

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Joined: Sep 18 2014
Posts: 5
Re: CC & 575 upgrade question

Quote:

...mod of your choice to the CC's original analog board

Are there only the Takky and Chris Lawson video mods that you are aware of? It seems only the Takky mod works with a stock CC, and I don't want to kill a 575 just to take its motherboard, so I plan to do the Takky if there's no advantageous alternative.

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Joined: Sep 18 2014
Posts: 5
Re: CC & 575 upgrade question

..and I'm done. One thing not mentioned on any site that I could find was that the 640 mod will cause an original CC to lose a level of colors unless additional video ram is installed, my CC went from 256 color capability to 16 colors max after the mod.