After you have connected your router to your PC using the console_cable you possibly need to use the second uart of the ADM5120 too. A description how to make this mod you find here.

Assuming you already made the First Uart Mod using a M232, not a telephone data cable, you have four free pins on your M232. Make the following connections:

ADM5120 PIN130 over an 1k resistor to MAX232 Pin 9.
ADM5120 PIN131 without resistor to MAX232 Pin 10.

For the other two pins first make sure, what you want, a serial device or an terminal:

The schematics on the console_cable-Page show you the connection if your router ist the serial device and your PC is the terminal. That meens the router is a device like a modem that you connect to the PC. You need a female DB9 connector on your router for that.

There should be -9...-12 V between Pin 3 and Pin 5 (GND).

M232 T[1,2]OUT - DB9 female Pin 2
M232 R[1,2]IN  - DB9 female Pin 3

But if your router should be the terminal and you want to connect a device like a modem to it you need a male DB9 connector and you have to change the RX and TX pins. That meens, a simple gender changer is not enough.

There should be -9...-12 V between Pin 2 and Pin 5 (GND).

M232 T[1,2]OUT - DB9 male Pin 3
M232 R[1,2]IN  - DB9 male Pin 2

Support for /dev/ttyS1 is included in the latest version of midge, but there are problems changing the baudrate at runtime. The following steps work:

• install the source tree as described in Howtos
• edit trunk/openwrt/build_mipsel/linux-2.4-adm5120/linux-2.4.32/arch/mips/am5120/serial.c, line 104 from

{baud_base:UART_115200bps_DIVISOR, port:KSEG1ADDR(UART1_BASE), irq:2, flags:STD_COM_FLAGS, type:SERIAL_IO_MEM}

to the baudrate you wish

{baud_base:UART_2400bps_DIVISOR, port:KSEG1ADDR(UART1_BASE), irq:2, flags:STD_COM_FLAGS, type:SERIAL_IO_MEM}

• build your firmware

You have to make additional settings at runtime described here.