InscrutableAudacity

I'm in the process of developing a couple of 16K games, and it occurred to me that I don't know how a 16k Speccy behaves when you try to read memory above $7FFF.

I've tried four different emulators, and they all produced different results: one always returned $00, one always returned $FF, another returned random values, and the last one seemingly ignored bit-15 of the address and returned a mirror of the ROM and 16k of RAM.

Since I realise many people would be playing the games on an emulator, I'll work on the assumption that the upper 32k of address space can't be relied on to hold any specific values; but I'm still curious what would happen on the actual hardware.

Anybody know what a r