C=64 core working with bad ram?

[zBeeble]

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.