This is a quite nice 68000 assembler with a very nice integrated editor.
Note that it *only* handles 68000 code, there is no support for 68020
or later CPUs. 
One bug that I have found is that when tell it to try to make instructions
PC relative it attempts to do so with BSET/BCLR also which results in
illegal instructions.

 PERMSSN    UID  GID    PACKED    SIZE  RATIO     CRC       STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
drwx--s---  3533/39          0       0 ****** -lhd- 0000 Jan 11  1997 McAsm/
-rw-------  3533/39        507     993  51.1% -lh5- 827e Mar 27  1991 McAsm/Contents.txt
-rw-------  3533/39      41558  125543  33.1% -lh5- 1465 Dec 13  1992 McAsm/MCAsm.doc
-rw-------  3533/39      80583  177772  45.3% -lh5- 0d6f Mar 28  1992 McAsm/McAsm
-rw-------  3533/39        272     430  63.3% -lh5- 5735 Jan 11  1997 McAsm/ReadMe.aminet
-rw-------  3533/39        356    1115  31.9% -lh5- 2779 Mar 27  1991 McAsm/Thisfilecamefrom.txt
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total         6 files  123276  305853  40.3%            Jan 16  1997