Another day, another step forward. I've synchronised the Emulator to the timer now, so instead of running at 50Mhz, it's running at 50 kHz.
I must check to see if its over clocked, because they can run up to about 65khz (400Khz clock, 6 cycles per instruction)
Drawing the pixels on the screen above, and doing nothing much else, runs about about 32 Frames a second.
Now, it is fairly slow as a method, because there are loops and lookups in that pixel drawing code, it would be much quicker just outputting four nibbles, but still, it's going to be like programming for the Studio 2 ; do the graphics first and get the frame rate passable, and then fit the game around it.