Help me trick out my new 575 logic card (for my CC)

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Joined: May 9 2015
Posts: 62

Hi folks....

After the disturbing death of my CC logic board (battery goo over about 1/4 to 1/3 of it), I decided to upgrade my CC. I have bought a 575 logic board and it arrived in the mail today. The previous owner had sent this logic card out and had it re caped.

I would like to populate it with the maxim amount of memory it can take. It has two SIMM cards in it now. The paper sticker on the back of each SIMM card says:

630-0045 and G9417

Can someone decode this for me? Are the above two SIMMS VRAM SIMMs or memory?

I have a single slot with a SIMM in it. The single SIMM has 8 chips on each side of the SIMM card. The only markings on that SIMM is V9388 and L1-96.

So, reading this FAQ:

I get the impression that I should buy a couple of 70ns and a couple of 80ns VRAM modules (SIMMs) to test with.

Can someone direct me to a source to buy what I need? Or perhaps you have some to sell?

The memory link on Chris's FAQ page is not working. What is the largest amount of memory I can put in this 575 logic board, and what is the proper name for it and where do I buy it? I googled "NEC D42565405G5" and nothing came up. This is suppose to be the 128MB SIMM. Anyone know of another source for a 128MB SIMM that would work?

I was able to locate the oscillator socket at Digi-Key (A462-ND), but Digi-Key no longer will stock or sell the 20.000MHz crystal oscillator (CTX119-ND). I did find that Mouser might be able to get it for me. It is a non stock item, but they can order it. Mouser tells me I should have email from them with in 3 days letting me know. Here is the link:

Reading the overclocking page by Chris Lawson:

Chris says:

"While you're speeding up the computer, you might as well put a full '040 into it. I have benchmarking results for a Q605 published here comparing the stock motherboard to a clocked one with a full '040. The full '040 will speed up math-related tasks such as JPEG rendering (common on WWW pages) by a factor of about five".

I can't read Chris's short hand. When he is speaking about a "full 040" is he talking about the main Motorola CPU in the middle of my 575? Would this be a Motorola 68040 running at 40Mhz? If so, is this CPU plug and play?

Because I am going to remove the SCSI hard drive and roll in a SD card (with a SCSI back side), I will have a little bit of power left over from the power supply. I am thinking of a heat sync and fan for this CPU. Any suggestions on a good place to grab 12V on the 575 logic board?

What is a Color Classic Enabler Pack and where do I get it? The link to the Mac 512 User Group still works, but searching the site turned up no Color Classic Enabler Pack.

So many of the links I follow are now dead. I am happy this forum is still working.

Any help or tips appreciated.

I am still trying to figure out how to attach a .jpg to email I post on this forum.

jack the new kid