This section discusses the differences between MASM 5.1 and MASM 6.0. Section A.2.1 provides information in addition to that found on the MASM 6.0 Quick Start card. The information in this section explains what changes you may need to make in order to get your MASM 5.1 code to run under MASM 6.0 in compatibility mode.
Note:
If you have not already done so, please read the Quick Start for MASM 5.0 and 5.1 Users card provided in your MASM 6.0 package.
Once your code runs in compatibility mode using OPTION M510 or the /Zm command-line option, you may want to modify your code so it runs under MASM 6.0 without the compatibility options. To learn how to do this, see Section A.2.2, “Using the OPTION Directive.”
You may notice that the .OBJ and .EXE files differ between MASM 5.1 and MASM 6.0. These differences do not necessarily indicate compatibility problems, since MASM 6.0 generates optimal encoding.