--- Net2/arch/i386/isa/ic/ns16550.h	2018/04/24 18:04:01	1.1
+++ Net2/arch/i386/isa/ic/ns16550.h	2018/04/24 18:20:13	1.1.1.2
@@ -30,7 +30,8 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	@(#)ns16550.h	7.1 (Berkeley) 5/9/91
+ *	from: @(#)ns16550.h	7.1 (Berkeley) 5/9/91
+ *	ns16550.h,v 1.3 1993/06/30 04:04:24 andrew Exp
  */
 
 /*
@@ -48,3 +49,4 @@
 #define	com_mcr		4	/* modem control register (R/W) */
 #define	com_lsr		5	/* line status register (R/W) */
 #define	com_msr		6	/* modem status register (R/W) */
+#define com_scratch	7	/* scratch register (R/W) */