ttyS(4) Device Drivers Manual ttyS(4) NAME ttyS - serial terminal lines DESCRIPTION ttyS[0-3] are character devices for the serial terminal lines. They are typically created by: mknod -m 660 /dev/ttyS0 c 4 64 # base address 0x3f8 mknod -m 660 /dev/ttyS1 c 4 65 # base address 0x2f8 mknod -m 660 /dev/ttyS2 c 4 66 # base address 0x3e8 mknod -m 660 /dev/ttyS3 c 4 67 # base address 0x2e8 chown root:tty /dev/ttyS[0-3] FILES /dev/ttyS[0-3] SEE ALSO chown(1), mknod(1), tty(4), agetty(8), mingetty(8), setserial(8) Linux man-pages 6.7 2023-10-31 ttyS(4)