Gold Card info request.

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Dave
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Gold Card info request.

Postby Dave » Sat May 25, 2019 6:58 pm

I don't have an unaltered, functioning Gold Card right now. Could someone with a Gold Card please check something for me?

I'm curious if the GC aliases the 2MB part of the memory map it uses through the entire memory map (so the 2MB repeats 8 times) or if it repeats at 4MB (as the GC uses the same INGOT as the SGC) or if it does not alias at all through the 16MB address range.

If the memory map does not alias through memory, it should be possible to expand the GC to 16MB. If it aliases at 4MB boundaries, it can be expanded to 4MB. If it aliases at 2MB boundaries, that removes all options.


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Pr0f
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Re: Gold Card info request.

Postby Pr0f » Sat May 25, 2019 7:28 pm

Dave,

Address lines A21, A22 and A23 are not connected to anything on the board, so my guess is the 2Mb will repeat through the address space.

That's from the original circuit diagram and also confirmed on the Tetroid Gold card.


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Dave
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Re: Gold Card info request.

Postby Dave » Sat May 25, 2019 7:53 pm

I have an idea for a daughter card that fits into the 68000 and INGOT PLCC sockets so it has access to all the lines on both ICs. So really, it's just a matter of how the decoding is done inside the INGOT. I can supply an external decoder, but I don't know the pinout of the INGOT so I don't know what signals are externally available.

Just brainstorming.

Nasta's been busy and I'm getting fidgety.


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Dave
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Re: Gold Card info request.

Postby Dave » Sat May 25, 2019 7:57 pm

I'm only considering the idea, because Tetroid in a move of genius kept the relative positions of the CPU, INGOT and floppy driver ICs 100% unchanged.



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