User Port (Serial IO)
The User Port is the port on the IO Board that has the same physical appearance as a USB 3.0 port, but it is merely using a USB 3.0 connector as a means for serial I/O communication. The port could potentially have various uses, but these are features that are currently implemented or upcoming:
SNAC (Serial Native Accessory Converter): This essentially means that a system's original controller can be connected (on supported cores) to be used as if they were connected to the original system. This means there is absolutely no lag unless it's native to the original system. Additionally, any original accessories should be compatible within reason (this won't make your original lightguns magically work on a LCD). Currently only one controller port is supported, but (depending on the core) can be swapped between the 1st and 2nd controller port in the core's OSD.
An adapter will be required that is mostly wire-to-wire plus level shifters to translate the DE-10 Nano's 3.3V IO pins to 5V used in older system's controllers. Cores with support:
- SNES (coming soon)
BlisSTer (coming soon): This is a combination of a USB hub board that also has a low latency controller interface via the Low-Latency API (LLAPI). With Bliss-Box style adapters this will allow you connect original controllers for various systems with extremely low latency. The upside of this is that you could technically use any compatible controller with any supported core, so you could use a Genesis controller on the NES core if you really wanted to. The downsize vs SNAC is that this will mostly/only work with controllers, so multi-taps and oddball accessories will generally not be compatible.