$compact
$optimize(3)

conn$module:
do;

/* CONNECT: Establish a "virtual terminal" connection through a         */
/* specified serial i/o port.  */

$INCLUDE(:INC:LTKSEL.LIT)

declare status word external;
declare (in$conn,out$conn) token external;
declare (ci$conn,co$conn) token external;
declare debug byte external;

declare break literally '1DH';
declare ctly  literally '19H';  /* ^C by typing ^]^Y */
declare ctlq  literally '11H';
declare ctls  literally '13H';
declare ctlc  literally '03H';
declare true  literally '0FFH';
declare false literally '00H';
declare null  literally '0';
declare cr    literally '0DH';
declare lf    literally '0AH';
declare crlf  literally 'cr,lf,null';

$INCLUDE(:INC:UREAD.EXT)
$INCLUDE(:INC:UWRITE.EXT)

declare iobuff(1024) byte public;

check$error: procedure(fatal) byte external;
	declare fatal byte;
end check$error;

print:	procedure(msg) external;
	declare msg pointer;
end print;

newline: procedure external; end newline;

sbreak: procedure byte external;
end sbreak;

send$setup: procedure external;
end send$setup;

connect:
	procedure public;
	declare (c,i,qbreak) byte;

	qbreak=false;
	if debug then
	  do;
	    call print(@('connecting to serial port $'));
/* something about which terminal line */
	    call newline;
		call print(@('to exit CONNECT mode type ^] C$'));
	    call newline;
	  end;
        do while (1);
	    c=DQ$READ(ci$conn,@iobuff,80,@status);
	    if check$error(0) then return;
loop:	    if c>0 then do;
		  if qbreak then do;
			qbreak=false;
			if iobuff(0)='C' then return;
			else if iobuff(0)='c' then return;
			else if iobuff(0)=ctly then iobuff(0)=ctlc;
			else if iobuff(0)='0' then iobuff(0)=null;
			else if iobuff(0)='?' then do;
				call print(@('Special characters are: B,C,?,^Y,0',crlf));
				c=c-1;
				if i>0 then call movb(@iobuff(1),@iobuff(0),c);
				goto loop;
				end;
			else if (iobuff(0)='B' or iobuff(0)='b') then do;
				call send$setup;
				i=sbreak;
				c=c-1;
				if i>0 then call movb(@iobuff(1),@iobuff(0),c);
				goto loop;
				end;
/*  add check for other characters.....otherwise ignore */
		  end;
		  do i=0 to c-1;
			if iobuff(i)=break then do;
			  if i>0 then do;
				call DQ$WRITE(out$conn,@iobuff,i,@status);
				if check$error(0) then return;
			  end;
			  c=c-i-1;
			  if c>0 then call movb(@iobuff(i+1),@iobuff,c);
			  qbreak=true;
			  goto loop;
			end;
		  end;
	      call DQ$WRITE(out$conn,@iobuff,c,@status);
	      if check$error(0) then return;
	    end;
	    c=DQ$READ(in$conn,@iobuff,40,@status);
	    if check$error(0) then return;
	    if c>0 then do;
	      call DQ$WRITE(co$conn,@iobuff,c,@status);
	      if check$error(0) then return;
	    end;
	  end;
end connect;

end conn$module;