Expansion slot : trying to find more infos (pic inside)

Rodpulsar

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Hi there :)

I'm working on an Amiga 1200 mod since some time now, and the last step for me is to create a cable between the processor expansion slot and my Apollo1260 (to put it backwards inside, more or less like on this pic :

https://www.amibay.com/attachment.php?attachmentid=65062

This pic comes from the great mod of jimbob005 here :
https://www.amibay.com/showthread.php?570-a1200-in-an-a600-case

But I can't seem to find specific informations between 2011 and today, specifically about that processor port hack (basically just wiring each pin, but he seems to have used a connector on the card side, which seems quite clean).

Thanks for any help or information !

Peace.

Rod
 

retrodave

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Hi Rod,

So you're basically trying to extend the A1200's CPU Slot allowing you to move the 1260 elsewhere in the box? If it helps, that'd be just a straight pin-n to pin-n extension cable, you can buy female IDC edge-connectors from good electronic component suppliers which would make the Amiga end nice and tidy, they might sell male edge-connector boards too with the right pitch (pin spacing). I'm not sure what jimbob005 has used, but if not but any spare PCB with a suitable male edge-connector could make up the other end - perhaps the remains of a donor accelerator board or an unwanted busboard pass-through? A1200 development boards might exist too with suitable connections on (though I've never seen one myself). Are you good with a soldering iron? Ribbon cable is hard to work with but not too bad if you handle it carefully and meter your connections well before powering on :)

Ian Stedman's great page has A1200 schematics and specs that will give you lots of A1200 CPU Slot info, as I said it's just a straight pin-to-pin extension though from the sound of your post. The only problem you might get perhaps is noise, if so maybe doubling the width of the ribbon cable and tying every other pin to ground might help screen out any interference - I wouldn't have thought that'd be necessary though.

I hope that helps! :) Good luck with your project - and don't forget to post the results to Amibay :D :D
 

Ed.D

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Correct me if I'm wrong somebody please. I think the A1200 card edge is the same as PCI and there are PCI extension cables available from various places.
 

BLTCON0

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Correct me if I'm wrong somebody please. I think the A1200 card edge is the same as PCI and there are PCI extension cables available from various places.

Definitely not PCI. You may be confusing it with the A600's trapdoor connector, I think a PCI slot can be used there.
 

Rodpulsar

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Well in fact the space of the pins, and between pins is the same as first PCI version (PCI 100/133). However the connector is not of the same length, and the space between the two blocks of pins is not at the same place. So it's not 100% compatible :)
 

retrodave

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I guess you could perhaps bodge it Rod - if you cut two PCI sockets carefully and used the edge connectors from two PCI development boards. As long as you could lock them stable mechanically and the join was right you might have a working solution :)
 

Rodpulsar

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This is EXACTLY what I did :D

So far it works when I test one by one each pin with only the cable and the card attached together.
As soon as I plug it onto the motherboard it doesn't work anymore. Comp boots (good new) but with a display error and the disk won't work. I guess I still have bad contacts...

The result so far :
20150728_183902.jpg

Close-up on the PCI connector :
20150728_183915.jpg

The cut is in a difficult place and that's probably the cause of my problem. I have to think again the connection...
 

Rodpulsar

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Ok so it works... but only with my ACA1231, not with the Apollo1260... odd... I will open a thread on this specific subject.
 
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