OpenMSX alternative front-end debugger with V9990 support showcasing Isometric engine protype on V9990 by Fernando García B1 mode.
Debugger already supports P1 mode (planes A and B) also.
This is a Work In Progress, but ideally will support all classic MSX video modes.
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https://www.youtube.com/watch?v=gTK4-rFP4UE