The Atari Eiffel PS/2 adapter allows you to connect a PS/2 keyboard and mouse to your Atari Mega ST(E) or Atari TT to the keyboard port (RJ12).
Although compatible in theory, the Atari Eiffel PS/2 adapter cannot be connected to an Atari STF or Atari STE which have an integrated keyboard, because it uses an RJ12 port (telephone cable) which the Atari STF and STE do not have. To use a PS/2 or USB mouse on an Atari STF or STE, rather use an adapter to plug into the joystick port instead.
This version of the adapter includes two joystick ports (Joy 0 and Joy 1) in addition to being able to connect a PS/2 format keyboard and mouse.
However I noticed that the joystick feature is not supported by all games. By doing some research it seems that there are several methods of joystick support by the Atari ST. The Eiffel adapter doesn’t emulate all of these methods, so it’s hit-and-miss.
The joystick ports also do not emulate the mouse function, so you cannot plug an Atari mouse into the joystick port.
I don’t recommend using a USB to PS/2 adapter to connect the mouse, as it doesn’t always work. Some claim that it works, but the tests I have done have never yielded good results. Preferably use a native PS/2 keyboard and mouse, with a ball or optical, both work.
The PIC microcontroler provided is already programmed, the adapter is Plug-and-Play.
To connect the adapter to your Atari, you will need a straight RJ12 (6P6C) cable (not included).