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Using Microsoft Flight Simulator 4.0 to test x86 emulator correctness?

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First post, by superfury

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I'm now wondering: what's the difference between selecting 8086, 80286 and 80386 when going through the setup steps when running the program? Does 80286 add extended memory support(HIMEM.SYS) while 80386 adds something more(virtual 8086 mode or 32-bit protected mode support)? Anyone knows if it's suitable for testing 32-bit CPUs completely(e.g. 80386 32-bit real/protected/VM86 app testing)?

Author of the UniPCemu emulator.
UniPCemu Git repository
UniPCemu for Android, Windows, PSP, Vita and Switch on itch.io

Reply 1 of 2, by filipetolhuizen

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I guess the 286 has something different. If you're running the game in a 386 CPU it won't list the 286 as a compatible CPU (but will allow 8086/8088).

Reply 2 of 2, by superfury

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Since it's running on both CPUs selectable with both modes, does that mean the parts/features it's using work without problems?

The only difference between the 80286 and 80386 instruction set is the new protected mode extensions and 32-bit instructions(as well as a few new instructions concerning new segments and bit instructions). One thing the 80286 mode might use(but the 80386 doesn't have without software emulation using the 80386 equivalent) is the 80286 LOADALL instruction afaik? Maybe it uses that with the 80286 mode setting? Although HIMEM.SYS could handle that?

The 80386 might use V86 mode or 32-bit protected mode, but since EMM386 doesn't run yet(with my last tests) I doubt it's using that(since it's running without problems)?

Author of the UniPCemu emulator.
UniPCemu Git repository
UniPCemu for Android, Windows, PSP, Vita and Switch on itch.io

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