The TH counter in the genesis controller code was increasing each
time the TH bit changed state instead of only in one direction.
Surprisingly it worked before, and fixing it made it not work in
Sonic 2, but after adding the 1.5ms timer to reset the TH counter,
it worked again. I guess Sonic2 only reads the 3 buttons instead
of all 6. It should now work with both 3 and 6 button games
Previously it would show a dump of whatever device was next scheduled
to step, if it was Debuggable, but now each debuggable device has a
flag for whether that device is being debugging, and a system flag
to disable it entirely. When the system flag is set, it will try
to enable debugging on the device labelled "cpu". I need to also add
a way of setting a breakpoint on a named device, which will enable
debugging of that device
It's better than it was but there are still minor drop outs due to
a buffer underrun I think (could be other timing issues related to
the update loop or something else). Right now, the audio chips
just have some code to produce sine waves for testing.
I've added skeleton devices for the sound chips, and added the bank
register and banked area of ram mapped to the Z80's bus. Sonic1 will
now run (if the ym2612 device's size is set to 0x1000 instead of 0x04)
Previously it was storing data in the registers, which was an array
of u8, but now it's storing eg. full addresses for the scroll tables
so that they don't need to be fetched from the register values and
converted every rendering. I was thinking this would maybe make
DMA debugging easier, in particular.
The controller th count was starting at 1 instead of 0 which caused
inputs to be read incorrectly, as well as the fact that inputs are
inverted.
The sprite fix now draws them in the right order so that ComradeOj's
sprite test renders correctly, but games still render them broken
because of some other bug yet to be found
For systems that legitimately use 0 for black, this causes a
problem, so I instead use 0xFFFFFFFF for the mask colour which
corresponds to transparent white in ARGB format, which minifb
doesn't support anyways
It was previously decrementing addresses if the direction was from
registers to memory, but that's incorrect. It should increment the
address always when using an addressing mode other than the ARecDec
mode. I also added a memory location to the test cases to test the
MOVEM instruction by comparing what memory was read/written (but it's
only one u32 because that's the minimum we need)
