Hello.
I am trying to write a very simple Delphi4 32-bit console app which toggles the RTS pin of the COM1 RS232 serial port.
What is the simplest way to do this?
I tried writing asm code (see below) but not surprisingly I got a run-time exception:
Exception EPrivilege in module z.exe at 00008254.
Privileged instruction.
Does Delphi4 have built-in support for toggling RTS? I could not find it.
Thank you.
procedure SetRTS;
asm
mov dx, 03fch; {get COM1 MCR}
in al,dx;
or al, 2; {set RTS}
out dx, al;
end;
procedure ClearRTS;
asm
mov dx, 03fch;
in al,dx;
and al, 0fdh;
out dx, al;
end;