scc(7)							 Miscellaneous Information Manual						    scc(7)

NAME

       scc - Serial keyboard/mouse/communications interface

SYNOPSIS

       controller   scc0   at tc0   slot 3   vector sccintr

DESCRIPTION

       Two  base  board  Zilog scc dual UARTS provide DEC 3000 series personal systems with keyboard, mouse, and serial communications interfaces.
       The serial communications interfaces can operate at baud rates from B50 to B57600 (see tty(7)).

       The driver for the scc interface supports hardware flow control using the Request to Send (RTS) and Clear  to  Send  (CTS)  signals.   When
       hardware  flow  control is enabled, the flow of input data is controlled by the RTS signal and the flow of output data is controlled by the
       CTS signal.  If the CTS signal is off, the driver will suspend output to that line until the CTS lead is reasserted.  Likewise, the  driver
       will  turn off the RTS lead to tell the device connected to the line to stop sending data as a result of congestion on the host side.  When
       the condition clears, the driver will turn on the RTS lead to tell the device to resume sending data.

       In alternate console configurations (that is, no graphics head), communications port 2 (/dev/tty01) becomes the system console. The  serial
       system console port always operates at 9600 BPS, 8-bits, no parity.  No modem or hardware flow control is supported.

RESTRICTIONS

       Data  communications  equipment attached to the console serial port in alternate console configurations must be set to 9600 BPS, 8-bits, no
       parity. The scc driver enforces this restriction.

       Only communications port 1 (/dev/tty00) includes full modem control.

FILES

       console terminal local terminal local terminal

RELATED INFORMATION

       console(7), devio(7), modem(7), tty(7), MAKEDEV(8) delim off

																	    scc(7)