I've discovered that when BCC32 passes the assembly code to the assembler, it deletes all "IN" and "OUT" words, therefore if you type "OUT DX, AL", the assembler will see "DX, AL" and give an error. This is to discourage people from directly accessing ports in Windows. To get around this use the actual machine code as follows:
use "DB 0xEE" instead of "OUT DX, AL"
use "DB 0xEC" instead of "IN AL, DX"
You should find that it works fine. It should fix similar problems in other Compilers as well.
Unfortunately, in NT/2000 and probably XP, I'm not sure, you'll need to use a program like [italic]UserPort[/italic] to allow access to the port you're trying to use.