Microsoft KB Archive/25260

How to Specify a Processor ID Number: Q25260

1.25 1.27 3.00 3.01 4.00 5.00 MS-DOS

Question: How can I make MASM take advantage of my machine’s processor?

Response: MASM allows for specification of processor type. This can be done as follows with the first entry in the program being one of the following types:


 * 1) .8086 for 8086 without 8087 math coprocessor
 * 2) .8087 for 8086 with 8087 math coprocessor
 * 3) .186 for 186 processor
 * 4) .286c for 286 without math coprocessor without protected instructions
 * 5) .286p for 286 without math coprocessor with protected instructions
 * 6) .287 for 286 with math coprocessor

It is important to note that it is still necessary to include an /E or /R option when invoking MASM to enable the use of floating point instructions.