ID Number: Q69540
6.00 | 6.00
MS-DOS | OS/2
Summary:
In the Macro Assembler (MASM) version 6.00, the opcode for a JMP to a
far address is shown in the listing file with the segment first, then
the offset. In the actual .OBJ file, the address is stored in the
reversed order (offset then segment).
More Information:
The following is the encoding for the JMP instruction from the listing
(.LST) file generated from the sample program below:
0000 EA ---- 0000 E jmp faddr
The above address for faddr (---- 0000) is displayed with the segment
listed first (----), then the offset(0000). Because the linker
resolves this address at link time, the actual segment and offset is
not known at assemble time, and is not listed in this file.
If you then look at the actual .OBJ or .EXE file produced by the above
code (by using CodeView, for example), you will see the offset first
in the file, then the segment.
This is expected behavior with MASM version 6.00 and is designed to
make the segment:offset more readable. This is different from MASM
version 5.10, which displayed the addresses for far JMP instructions
in the reversed (offset then segment) form.
Sample Code
-----------
; Assemble options needed: /c /Fl
.MODEL LARGE
EXTRN faddr:far
.CODE
jmp faddr
END