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obitus1990
New Orleans, LA, USA

Posted Sun Nov 17, 2019 6:55 pm

My nearly finished A2000 build, from Floppie209’s open sourced motherboard files. Fully socketed, Rev 6.x motherboard. I am awaiting a few parts to complete it, including a DIY megachip kit, the Zorro, ISA, Video & CPU slots, the reset generator IC and a bipolar transistor (both obsolete parts and hard to find). Then I’ll add all the ports and test it out.

The other two pics are a DIY video hybrid known as the VIDIOT, but this version is special because it outputs to an SVIDEO port as well. All hand assembled by me, sans one resistor that went flying when opening the strip it came in...another is on order.

Many thanks to Zee Germanz of A1K again, for another great retro project!

E16B57A9-FC3C-4423-B84A-BCA1B66AECB7.jpeg
78A4770A-84B0-4295-8375-3D1E942F3049.jpeg
C6DEDF68-0B6F-4379-ABC9-1BAD2E881870.jpeg

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intric8
Seattle, WA, USA
Website

Posted Sun Nov 17, 2019 9:26 pm

GORGEOUS WORK!

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grshaw

Posted Mon Nov 18, 2019 11:33 am

Agreed. Really great work.

Could I ask a question please? Where did you source the Zorro II + ISA connectors from? I am having trouble sourcing these myself. Also - same question but for the sockets? I am sure the sockets are there on Mouser, however, I cannot find them. Also - the Power Connector.

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obitus1990
New Orleans, LA, USA

Posted Mon Nov 18, 2019 8:26 pm

I’ll grab the ISA slots from a dead pentium board I have already. You can get Zorro slots (100 pole) connectors on Mouser, they go in and out of stock frequently.
The power connector can be found on Amazon! Mouser has a minimum 1000 pieces order for Molex to produce a run. Someone posted the link on the Amiga Facebook group yesterday I think.
Sockets were bought from Mouser (harder to find ones like the 48 pin ones and the CPU) but all the others were bought from Jameco, which is much cheaper than Mouser or digikey.


Here is the power connector:

https://www.amazon.com/26-60-4140-Board ... B00T73TIUE

User avatar
grshaw

Posted Tue Nov 19, 2019 6:26 am

So, I found the Power connector available in unit quantities on Digikey UK:
https://www.digikey.co.uk/short/pvcp8q

Once you know what to look for ( i.e. 26-60-4140 ) it becomes much easier.

Thanks for your help Obitus1990. :D

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grshaw

Posted Sat Dec 07, 2019 8:15 am

Hey there,

I am continuing with my build at the moment. R215 is a bit of an odd one. Do you have a close up image of what you are supposed to do here? I have been looking at your jpeg above. It has been very helpful to me. However, it doesn't really have a high enough resolution in this case. Looks like one of the two legs of the resistor needs to be cut short and surface mounted?

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obitus1990
New Orleans, LA, USA

Posted Sat Dec 14, 2019 1:28 pm

Yes, that’s correct about the R215.

I’ve finished my build, but unfortunately it doesn’t work 100% yet. Only 512k of RAM is detected by workbench and the colors are all messed up. I’ve been hunting for days now to find the bug with no luck.

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grshaw

Posted Sun Dec 15, 2019 2:07 pm

Thanks for the advice about R215.

Sorry it’s not working 100%. However, what you are describing sounds fixable. The nightmare scenario would be smoke and nothing more on initial power up. J101 switches between 512 / 1024 K of Chip RAM. Do you have that set for 1024 K?

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obitus1990
New Orleans, LA, USA

Posted Wed Dec 18, 2019 8:38 pm

I've tried jumpering it both ways, still have the same issue. I went back and reflowed every single custom chip to make sure I didn't have a bad solder joint, but still no improvement. I also reflowed all of the RAM, and tried a completely different set with the same result. I guess I'll reflow all of the logic ICs next.

User avatar
grshaw

Posted Mon Dec 23, 2019 12:03 pm

This sounds like a lot of work. I hope it goes well. I cannot think of anything else to suggest. But I can wish you the very best of luck with it. :D





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