Edit the syslinux.cfg file on your floppy and
add the two following statements:
serial 0 19200 at the top of your file
append console=ttyS0,19200
The syntax of the serial statement is as follows:
SERIAL port [baurate]. This enables a serial port to act as the console. "port" is a number (0 = ttyS0 = com1, etc.). If "baurate" is omitted, the baud rate defaults to 9600 bps. The serial parameters are hardcoded to be 8 bits, no parity, 1 stop bit.
The append statement add one or more options to the kernel command line.
Your syslinux.cfg file will look like:
serial 0 19200 display syslinux.dpy timeout 0 append console=ttyS0,19200 default linux initrd=initrd.lrp init=/linuxrc rw root=/dev/ram0 boot=/dev/fd0u1680:msdos PKGPATH=/dev/fd0u1680 LRP=root,etc,local,modules,iptables,pump,keyboard,shorwall,ulogd,dnscache,weblet