Hi.
This board is supposed to work with any tachometer. I have tested 5 different models and they worked fine. All the tachometers work in the same way so I feel confident you can't find one not supported.
The tacho has at least 3 wires: 12V and ground for the power, and a control wire to drive the niddle. If the tacho has the light (very likely) you have another pair of wires which go to the 12V and the ground again. So the board has 3 terminals: the 12V, the ground and the control terminal, where you connect the 3 (or 5) wires from the tacho.
I wrote the software myself. It is an external application with plugins. Every plugin supports a different simulator. In this way it is more modular and when I want to support a new simulator I just have to add a new plugin. Only two days ago I added the plugin for IRacing.
Speedos are a bit tricky because they can be either mechanical (work with the spinning cable from the wheel) or electronic.
The first type is not supported because I should make the cable spin using an electric motor or something like that. Too messy for me.
The second type works with the same principle of tachometer's and should work with my board. But I haven't done many tests so I can't support it for now, although it is in my todo list.
The software as an option to use a tacho as a speedo: you connect a tachometer but you display the speed. Of course you first have to repaint/replace the dial.
Anyway supporting speedos has a very high priority for me and I am sure quite sure it is technically possible, may be with a software or firmware upgrade.
In the next weeks I am going to put online the website
www.symprojects.com which is the place from which to download software and firmware upgrades, as well as new plugins.
There is another product I have been working on and it is a USB gear indicator as cheap as possible, hopefully less than £20.
Will be ready in 4 weeks time.
Regards.