Getting Started Linux Keyboard drivers PS2Adapt details

Connecting the PS2Adapt evaluation board to the ST40 needs a little explanation. Only one of the ST40 seral ports provides flow control signals, and these are not always connected to the serial connectors. The PS2Adapt expects flow control signals to be active, and so needs to be fooled into thinking they are. In particular RTS needs to be held low (active). This can be done using a specail serial cable, but an alternative is to use the pins which would normally be used for synchronous operation:

• Short JP8 pins 1 to 4.
• Remove jumper JP9 which is shorting pins 2-7.

     +--------------------+
     |                    |
     |  +-+JP5            |
     |  |||               |
     |  |||               |
     |  |.|               |
     |  +-+               |
     |                    |
     |                    |
     |                    |
     |                    |
     |                    |
     |    JP9+--+         |
     |       |--|         |
     |       |..|         |
     |       |--|         |
     |       |--|         |
     |       +--+         |
     |   +-+JP6           |
     |   |.|              |
     |   |||              |
     |   |||              |
     |   +-+              |
     |                    |
     |                    |
     +--------------------+

Switches S1 is used to set the baud rate:

  S0  switch1 : 0 (on)  \
  S1  switch2 : 1 (off)  > baud
  S2  switch3 : 1 (off) /
  S3  switch4 : 2 (off) - asynchronous

The selects 9600 baud, which is the rate expected by inputattach.