tvm(row.u1.r, column.u1.r, text.i1a.r, num_chars.i2.r [,fcolor.i1.r] 
	    [,bcolor.i1.r] [,blink.i1.r])

	tvm_c(row.i4.v, column.i4.v, text.i1a.r, num_chars.i4.v [,colors.i4.v])

	This routine will perform I/O to the color TV.

	row	starting TV row for the transfer
	column	starting TV column for the transfer
	text	user buffer of ASCII data to be read or written, one
		character per byte
	nchars 	number of ASCII characters to be read from or  written  to
	        the TV screen.  If the value of NCHARS is negative, a read
		operation is performed.  If NCHARS is  positive,  a  write
		operation is performed. 
	fcolor  an optional integer argument which contains the foreground
	 	color code.  The default foreground color  is  white.  See
	        COLOR CODES below. 
	bcolor  an optional integer argument which contains the background
		color code.  The default background color  is  black.  See
	        COLOR CODES below. 
	blink  	an optional integer argument which contains the blink code.
		Blink codes are as follows:

			0 = don't blink characters (default)
			1 = blink characters

	The COLOR CODES are as follows:

		0 = black  (default background color)
		1 = blue
		2 = green
		3 = cyan (green + blue)
		4 = red
		5 = magenta (red + blue)
		6 = yellow (red + green)
		7 = white (red + green + blue)  (default foreground color)

	NOTE:  In order to minimize I/O overhead, commands from the TVxxxx 
	routines are buffered.  The buffer is sent to the display under the 
	following conditions:  (1) buffer is full and more data needs to be 
	put in it, (2) user calls the INTYPE routine, (3) user calls the 
	TVFLSH routine, (4) user does a TV read operation.

	This function requires the following include files:


	Related functions:

	window_tvm(_c), btvm(_c)