The ASCII Write instruction works in both System and User modes.
Many other ASCII serial port instructions, including AWA, ARL, ACB, etc. require the User mode features or the input buffer, so they do require the port be in User mode.
as Ken said, either should work ... I didn't go into any real detail - just enough to show that "yes, it CAN be done" ... it looked like the OP just wanted a "getting started" setup ... hopefully this will do the trick ... it worked fine in the lab - and only took a few minutes to get going ...
The ASCII Write instruction works in both System and User modes.
Many other ASCII serial port instructions, including AWA, ARL, ACB, etc. require the User mode features or the input buffer, so they do require the port be in User mode.
as Ken said, either should work ... I didn't go into any real detail - just enough to show that "yes, it CAN be done" ... it looked like the OP just wanted a "getting started" setup ... hopefully this will do the trick ... it worked fine in the lab - and only took a few minutes to get going ...