MicroMac Accelerator card for Color Classic (not working)

ouroboros

New Tinkerer
Nov 29, 2022
25
8
3
I recently purchased this accelerator card for a Color Classic I have. It did not have a 68030 cpu installed on it, so I soldered in a socket and plugged a known working one in that came from a SE/30.

When I install the card and turn the Color Classic on, I heard the hard drive and fan spin, but no chime and no boot. I thought maybe it needed some time. 3 or so minutes pass with no change. Am I doing something wrong? Do I need to remove the 68020?

I do not have much knowledge on these types of cards. I'd assume it was "plug and play" or at least where it would boot normally and not be recognized without specific software. The seller was reputable and said it was tested and worked.

Edit 1 : Doing some research I think I misunderstood how this card works. Thinking it would be 2x 16mhz 030 working together (the one on the logic board and one on this PDS board), but this site says it is a single 32mhz 030 doing the work. So, I'm thinking I can get any 32mhz 030 on ebay, plop it in, and it should function properly?

Edit 2 : I did more searching, and cannot find any photos or evidence of this card having a 020 installed. I don't know what that means. Anyway, I purchased a 33mhz 030 on eBay and should be delivered in about a week. In the meantime, I'm going to keep plugging away at desoldering the 020. I purchased a socket for the 020 portion of the card that I will install that so any future desoldering won't be needed.

Thanks!

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lobust

Tinkerer
Nov 14, 2021
51
34
18
When you got the board the 030 was not populated and the 020 was already installed?

I don't have one of these but I'm reasonably certain that 020 is not supposed to be there. There is no mention of an 020 version of this accelerator on the MicroMac website, and every other picture I can find of this accelerator does not have an 020 installed there. I think that position on the board was intended as an alternative connecting option that was never used.

Maybe someone before you has been messing with it already, or maybe (I really doubt it as I can find nothing to support the theory) there was a different 020 accelerator specifically for the LC based on the same board and later discontinued?

If you remove the 020 the card might work, hopefully it has not been fried...
 

ouroboros

New Tinkerer
Nov 29, 2022
25
8
3
When you got the board the 030 was not populated and the 020 was already installed?

I don't have one of these but I'm reasonably certain that 020 is not supposed to be there. There is no mention of an 020 version of this accelerator on the MicroMac website, and every other picture I can find of this accelerator does not have an 020 installed there. I think that position on the board was intended as an alternative connecting option that was never used.

Maybe someone before you has been messing with it already, or maybe (I really doubt it as I can find nothing to support the theory) there was a different 020 accelerator specifically for the LC based on the same board and later discontinued?

If you remove the 020 the card might work, hopefully it has not been fried...
Thanks for the reply.

Yes - when I first purchased the card, it only had the 020 and the FPU populated. I added a socket for the 030 and placed an 030 from an SE/30 I have in it and then inserted the card in my Color Classic and it wouldn't boot. I figured I would have to take the 020 out completely, but desoldering that has been somewhat of a struggle just using a copper wick.

As I mentioned in my edit, it looks like MicroMac used a 30mhz 030 CPU on the card and I put in a 16mhz, so that might also be the issue of it not booting. The card may sense the wrong speed? I'm not sure.

I hope having both CPUs on the card didn't fry it when I put it in the Color Classic...yeesh...
 

ouroboros

New Tinkerer
Nov 29, 2022
25
8
3
It definitely looks like that 68020 should not be there at all, based on this photo of a presumably stock unit. If yours came with one, but the 68030 socket empty, I'd wager that someone removed the 030 from it to swap into a Mac, then took the 020 from that Mac and, for whatever reason, felt compelled to put it on the card.
Thank you for your response and validating what has been my assumption while investigating. My 33mhz 030 should arrive early next week. There are just a few pesky pins that the solder is being difficult getting to and the 020 will be out. I don't want to be hasty and risk ripping the traces so I'm taking my time.

I also have never seen the site you referred to. There are a few other cards or upgrades that I found in computers and have no idea what they do. This site may give me some clues.

I think the 68020 is maybe the proof that it was a prototype unit because the 68881 was made for it initially.

Btw, on MicroMac website they don’t mention this version. The 68020 was never populated in production units:
I thought this as well, but cards that have the 030 also have the 68881 FPU, so I think that was standard.
 

ouroboros

New Tinkerer
Nov 29, 2022
25
8
3
Update : I had to buy a desoldering gun and a reflow station to get the 020 out without brute force. But it’s out, threw the card back in the CC and it booted up no problem. I still need to install a benchmark program to make sure it’s reading the accelerator @33mhz but I think this is very promising. Thanks to all who offered their help!
 
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KennyPowers

Active Tinkerer
Jun 27, 2022
278
315
63
FWIW, I've seen versions of this card with the 020 instead of the 030. There's one on ebay right now:

s-l1600 (4).jpg s-l1600 (5).jpg

There are some noteable differences between that card and the card in the first post:
  1. U4 is populated
  2. resistor at JP1 instead of JP2
  3. 20Mhz 020 vs 33Mhz 020 (though maybe running the 20Mhz part at 25Mhz?)
  4. made in the US vs Taiwan