Limitations-----------* requires 640k linear RAM (64k base + 576k high).* stack writes generated by PUSH AF and CALL instructions, even when done within screen memory ($4000-$5AFF), won't get reflected on display.* the Z80 address space is 65537 bytes: a word write to $FFFF will do a (harmless) write to $010000, and a word read will read that value back instead of fetching MSB from $0000.* R register contents is fake.* block instructions (LDIR & co.) won't accept interrupts until done.* undocumented flags are only set when it costed nothing to take some care of them.* Z80 instruction timings are not exact and not even proportional: instructions are just executed as fast as possible. Therefore programs depending on precise timings will fail. This is especially visible (or rather audible) on tunes: VBL-driven ones will keep the tempo, while ones depending on delay loops will suffer clearly audible tempo fluctuations.* tunes also sound horrible when they rely on Z80 speed which under emulation is sometimes insufficient (Fairlight, Trapdoor).