Extension of BASIC & SYNTAX ERROR

[MIRKOSOFT]

Hi!

I'm working on own extension of BASIC7.

I have finished some commands, but...

If command has no parameter everytime all is ok.
When I add any parameter, e.g.:
$10 (directory drive #10)
... code works ok, but final output after directory is ?SYNTAX ERROR.

As I know on C64 is possible to disable output errors:
POKE768,139 - enables
POKE768,64 - disables...

Also I want to ask how to include to code that RUN/STOP stops listing etc..
On C64 it works with implementing JSR $A82C

I'm grateful for every help.

Miro