I have been using the DX Doubler (DXD) by Top Ten devices as my central Station controller. This box is widely known as an SO2R box for Contesters using two radios, but it is a great solution for anyone with two radios who wants to use a single Mike, Headset, Keyer, etc. Instead of buying a radio with two receivers, I bought a second complete radio and this box. Total cost was probably not much more and if one radio dies, I am still on the air.
In case you haven’t noticed, most PCs no longer come with an installed connector for a Parallel (LPT) interface. For those of us using the DXD, I see there is a Universal USB-to-LPT converter available and I have heard this will work with the DXD box. Last time I looked, these were over $100.
I am investigating a dedicated interface for N1MM+ software and the DXD box, using a small Arduino computer with USB to connect in place of the LPT interface. This approach provides more control over the DXD box, perhaps allowing me to add some customization to the features. The USB interface will include lines for CW Keying and PTT. If anyone has already done this, please let me know. If not, and you are interested in what I am doing, let me know that as well.