I made it !

I had to correct a couple of blunders (see the diagram below) and now the system woks (almost) as expected !

Not all the forbidden/impossible codes are prevented :

- IN and OUT seem to allow the IMM4 and REG modes, though the output binary code will be decoded "correctly"

- INV allows SND to be output

- probably some other obscure combinations are possible

However this panel is only one half of the ASM equation : the disassembler display will prevail over the buttons configuration.

This is why some markings are missing : when programming, look at the output and trust the display, don't stare at the buttons.

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(I'll have to shoot a video...)

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