The text output format of some subcommands is different in mdb(1). Macro files are formatted using the same rules, but scripts that depend on the output of other subcommands may need to be modified.
The watchpoint length specifier syntax in mdb(1) is different from the syntax described in adb(1). The adb(1) watchpoint commands :w, :a, and :p allow an integer length (in bytes) to be inserted between the colon and the command character. In mdb(1), the count should be specified following the initial address as a repeat count.
The /m, /*m, ?m, and ?*m format specifiers are not recognized or supported by mdb(1).