Reply 620 of 622, by superfury
Hmmm.... Just discovered something weird trying to boot Windows NT 4.0 to verify CPU behviour to be working properly still.
Somehow it reaches what seems to be opcode 84h (TEST r/m8,r8), but fails to fetch the modr/m parameters for some weird reason?
Looking at the fetching precalcs, it looks like the settings aren't properly retrieved from the instruction parameter lookup table, if at all (perhaps it points to another opcode, so never fetched properly)?
Edit: Hmmm... Now after some more testing (Windows 95 again), I see it failing on a opcode seemingly page faulting and failing somehow (proceeding to execute an invalid instruction).
Edit: After improving that, now Windows 95 fails to boot, telling there's not enough memory to load the registry?
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