Raspberry Pi advice

[Olivier]

Hi,

I am not sure I am on the right list, if not, please help and point me
to the correct one.

Many years ago, I wrote an application that tale two mouse buttons as
input and uses a relay card, interfaced to the printer port, as output.

It become more and more difficult to find motherboard with printer port,
plus some changes on the way the OS is treating the mouse, makes me
consider moving to Raspberry Pi.

My questions are the following:
- which version buying? 2B or 3B?

- how GPIO does GPIO work? I need one input to generate interupts and
  the other one to generate interupts but that I can also be able to
  pull the value when there has been no interrupt. Is that possible?

- would it be possible to use the GPIO to generate a signal to sound
  like a siren?

Best regards and thanks for the help,

Olivier
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