HAAS and other machine tool builders usually do, but Tormach lacks easy-to-access technical documentation such as this.
The Tormach website has PDFs of the instructions for all their machines, PathPilot programming and the various machine accessories available to download without even registering for an account or proving you own a machine. Machine self-service instructions are included for owner self-service. Schematics for the machine and controller board information are included in the machine’s instruction manual. Machines and boards/parts that are end of life have schematics and firmware on GitHub to provide documentation to further their position in support of consumer right to repair.
The source for the control software, PathPilot, to modify as you please, is on your controller. They provide free technical support, for the life of the machine, even if you are not the original owner. Contact support directly (this forum is mostly for owners to chat with each other) for assistance.
The USB I/O board is mentioned in the 1100 MX manual several times. Documentation for that device is also posted on the website as well.
Here is an example of a similar implementation/solution for ETS air blast in terms of electronics and hardware.