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Are different memory banks special?

G'day!

What I want to know is whether there is anything special about the 3
different banks of RAM in an apple ][?

I'm asking because I have come to the conclusion that most of the RAM is
indeed quite dead on my poor little clone ][.

I have seen a 256k 30 pin SIMM wired into a C=64 in the past, which made
perfect sense to me really. I couldn't see why it wouldn't work. So I was
considering doing the same a little more gracefully.
It wouldn't be able to access the higher areas of the SIMM though. I
wouldn't want it to anyway because it wouldn't be refreshed.

For those of you who are envisaging using something to refresh etc, and
using bigger SIMMS banked in, stop right there. SIMMS <= 256k share the
same refresh scheme as the DRAM chips. I can never remember whether it's
RAS before CAS or the other way around.
Admittedly I have seen and have documents on using the different DRAMs on
things like the Z80, but it involves more circuitry, and frankly I couldn't
be bothered.

I'm now fairly convinced that it's dead RAM that's stopping it working.
1-bit ram may be a pain mostly, but at least I can use an ASCII table to
figure out which bit is broken. It seems like I can't find 8 working chips!

One other question. I'm asking because I'm doubting myself. Looking at an
apple][ board, 6502 and slots up back, CHARGEN etc up front, which is the
lsb column of RAM. The left or the right?

Thanks,
Tristan.

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