C=64 core working with bad ram?

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zBeeble
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C=64 core working with bad ram?

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I have the outcome of a curious experiment to report. It begs the question: What does the C=64 core use the RAM module for? Or maybe more correctly, how does it use it?

Here's the setup. I seem to have a broken RAM module. I've attached two images. One is the memtest core running --- clearly errors --- doesn't even detect a size. I also attached an image of the Amiga core booting. Since they say the lines are evidence of bad ram, I'm assuming that the "bad ram" is a one-bit stuck on.

However, C=64 runs. I even wrote a little test program to exercise memory. I would think a one-bit would fubar anything, but since It runs, I wrote a little basic to create 1000 strings of a regular nature ... then even a regularly changing length in case I was missing something ... and that all seem to work.

Does the C=64, say, only use the low byte of the pair (I'm led to believe that SDRAM is 16 bit)? I've also asked before if someone might have a bit of a memory map... nobody's replied to that yet.
Attachments
mister Amiga failing --- note lines on screen.
mister Amiga failing --- note lines on screen.
failed-mister-amiga.jpg (153.86 KiB) Viewed 1531 times
mister memtest failing
mister memtest failing
failed-mister-memtest.jpg (111.8 KiB) Viewed 1531 times
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