Questions tagged [80287]

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What happens if an invalid opcode is executed on a 287/387 math coprocessor?

https://groups.google.com/g/comp.os.msdos.programmer/c/Lds3MJAgSl0/m/y8zfPt-bMskJ I assume that the 287/387 math coprocessors do not have the same illegal opcode exception that the 286/386 processors ...
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Is it possible to trap 387 FPU opcodes on a 287 connected to a 386?

The 8087 and 287 FPUs were designed before the IEEE 754 standard was released. Because of this, they contain some instructions which are not compliant with it. When the 387 was released in 1987, it ...
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