OK, the changes to GAS parsing is done. I think this should make it easier to find problems. So here's a test file with lots of errors:

    eric@compaq:~/dev/tios/src/gas_test$ cat gastest.asm
        mov r1
        mov r1+,r2
        mov r1,r2+
        inv r1, r2
        inv r

And here's the result from the new parsing code:

    eric@compaq:~/dev/tios/src/gas_test$ tms9900-gas gastest.asm
    gastest.asm: Assembler messages:
    gastest.asm:1: Error: unexpected end of line
    gastest.asm:2: Error: unexpected character at "+,r2"
    gastest.asm:3: Error: unexpected character at "+"
    gastest.asm:4: Error: unexpected character at ",r2"
    Invalid register starting at "r"
    gastest.asm:5: Error: missing argument

Could this be better? Maybe, but it's a lot better than before. Time to get back to floating point code.