EOR performs exclusive-or, not inclusive-or.

(That was awkward.)
Git doesn't ignore main go6502 directory.
Via6522 IRA/IRB reads use ORA/ORB for lines selected as output.

This seems to be correct for IRB.

Reading IRA for outputs should actually read the input pin states, which
isn't currently supported in this emulator anyway.
Via6522 SpiDebugger; limited functionality / configurability.
via6522: handleDataWrite works for both ports, all PCR modes.
ssd1306: OLED emulator (ultra-subset) on VIA port B.

Ignores commands.
Reads a single screen worth of data bytes.
Outputs to a PNG on close.