--------------------------
NEW XBIOS CALLS FOR THE TT
--------------------------

Warning: Use of these calls is restricted to the TT only.  For compatibilty
with other Atari computers use of these calls should be limited to those
applications which will require porting due to other incompatibility.

	(80) _EsetShift
	     WORD _EsetShift(shftMode)
	     WORD shftMode
		  Set the TT shift mode register to shftMode.
		  
			Bit assignments
			|S--H-MMM----BBBB|
			 |  | | |    |  |
			 |  | | |     -------	Bank
			 |  |  --------------	Mode
			 |  |			000 320x200x4
			 |  |			001 640x200x2
			 |  |			010 640x400x1
			 |  |			100 640x480x4
			 |  |			110 1280x960x1
			 |  |			111 320x480x8
			 |   ----------------	Hyper Mono
			  -------------------	Sample & Hold

		call always returns old shift mode register value.

	Note: For more information on Hyper Mono see: _EsetGray.  Also
	      the values returned by Getrez() correspond to the Mode
	      information given here. Also it is easier to change
	      individual elements of this register using the specialized
	      calls below.  They should be used whenever possible.

	(81) _EgetShift
	     WORD _EgetShift()
		   Returns the current shift mode register value.
                   
	(82) _EsetBank
             WORD _EsetBank(bankNum)
             WORD bankNum;
                   Set bank number (0-15) for active TT color Lookup Table.
                   This call also maps the current bank's colors to the old
                   ST color lookup Table. The bank is set imediately.
                   Function always returns old bankNum. If 'bankNum' is
                   negative, the hardware register is not altered.

	(83) _EsetColor
             WORD _EsetColor(colorNum, color)
             WORD colorNum, color;
                   Set the absolute entry 'colorNum' in the TT color LookUp
                   table to the given color. Color is set imediately.
                   Function always returns the old color. If 'color' is
                   negative, the hardware register is not altered.

	(84) _EsetPalette
             VOID _EsetPalette(colorNum, count, palettePtr)
             WORD colorNum, count;
             LONG palettePtr;
                   Set the contents of a contiguous set of TT hardware
                   palette registers with the words pointed to by 'palettePtr'.
                   'palettePtr' must fall on a word boundary. The set of
                   registers loaded begins with LUT register 'colorNum'
                   and extends for 'count' words. The function sets the
                   pallete immediately.


	(85) _EgetPalette
             VOID _EgetPalette(colorNum, count, palettePtr)
             WORD colorNum, count;
             LONG palettePtr;
                   Copy the contents of of a contiguous set of TT hardware
                   color LookUp Table registers starting with register
                   'colorNum' into the area pointed to by 'palettePtr'.
                   'count' words are transfed into the area. 'palettePtr'
                   must fall on a word boundary.


        (86) _EsetGray
             WORD _EsetGray(switch)
             WORD switch;
		Set the manner in which the color LookUp Table data is
		interpreted by the display hardware. A 'switch' value of 
		zero directs the display hardware to interpret the LUT
		data as color, 4 bits for each of the three components. 
		With a non-zero 'switch' value, the upper byte of the LUT
		entry is ignored and the lower byte alone represents one 
		of 256 gray levels. Function always returns the old switch
                switch value (a non-zero value means 'switch' is set).
                On input if 'switch' is set to a negative value, the hardware
                register is not altered. 


	  (87) _EsetSmear
               WORD _EsetSmear(switch)
               WORD switch;
		Set the video smear mode. A 'switch' value of zero
		indicates normal display mode while a non-zero value
		instructs the display hardware to repeat (smear) the last
		non-zero color encountered whenever zero values are retrieved.
		Function always returns the old switch value (a non-zero value
                means 'switch' is set). On input, if 'switch' is set to a 
                negative value, the hardware register is not altered. 
