Why are we going to rewrite the game code if we already have the game, and all it needs are better graphics and sound?
But, how can you get 256 colour modes with a Spectrum emulator instead of the colours the original games have?

The idea is: in one hand we´ve got the speccy emulator with its memory zone, and in the other we emulate a Z80 which works with 64 bit registers instead of 8 bit, and with a memory map with positions of 64 bit instead of 8.

Each time a z80 instruction is emulated, the same instruction is simulated with data always supposed to be graphics. I´ve named this parallel processor Z80_GFX. Z80_GFX modifies its memory zone accordig to the instructions and doesn´t do anything with Z80´s memory zone. What have we archieved? A faithful emulation of Z80 and a memory zone from which we can obtain 256 colour graphics.

One thing must be clear: graphics don´t get 256 colours by magic. You must work on them. We´ve got some tools that allow from a SNA file the modification of the graphics with a determined 256 colour palette, generating a GFX file that contains the colour definition in 8 planes (256 colours). The Z80_GFX processor will use this data afterwards