scc(7)scc(7)NAMEscc - 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 hard‐
ware 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 con‐
dition 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), commu‐
nications 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
SEE ALSOconsole(7), devio(7), modem(7), tty(7), MAKEDEV(8)scc(7)