EXPERIMENTAL!! jump table address decoder + support 24k and 32k drive roms

[penfold42]

For review and discussion only at this stage..

It does work - by work I mean a d64copy works fine. I haven’t tested more yet.

What’s the best way to profile this ?

At the expense of a little ram, this should be quicker - certainly more predictable.

I’m no c++ dev, but maybe a MemoryDevice base class for the VIA, rom and ram would make this much cleaner. The intermediate functions are horrible.

The big advantage is zero additional run time overhead as we add more config options - additonal rom, ram, 1581, 1571 support and so forth

[pi1541]

This is how VICE does it and it is cleaner.
Performance wise non consecutive case statements assemble to jumps anyway so it should be the same.

Just be careful though and make sure that everything is still mapped correctly.

readNULL returning 0 will break a lot of copy protections.
It should return address >> 8

[penfold42]

I’ve done the >>8 but closing for now - will re open when I look at cleaning it up properly

[penfold42]

Can you pls take another peek at this ?

I’ve added support for 24k and 32k drive roms (like dolphin and sjiffy)

[penfold42]

This has merge conflicts with my PR #72
If you want to merge both this weekend, merge one and I’ll clean the other up