Beta core for PSXNICCC demo and progress (Patreon)

Hi everyone,

a little warning at the very beginning: this is the first beta version for the PSX core.

The only useful thing you can do with it is viewing the PSXNICCC demo on your own MiSTer. It cannot play any games or CDs yet!

The setup (readme is included) also needs additional steps. So this is only for the most enthusiatic users!

Still, I wanted to make make sure you have something you can try yourself if you are really eager to do so.

Please understand that I cannot give support at this point if something isn't working for you. Future version will be more mature.

I also wanted to report on the progress of the last weak:

GPU: 

Most GPU features are implemented.  The only features missing now are VRAM readback and Dithering. Also bugs and edge cases remain to be fixed later. 

CPU: 

- Exception handling and Interrupts are now supported.

- fixed memory read/write bugs (testroms now passed)

Other Components:

- The basic Joypad communication interface for Digital Pad is working. Buttons handling is still open to be finished.

- Interrupt handling module is complete

That's it for this week. 

Have fun!