We just do not have a CURSOR in the emulation here. I think there might be something missing on the display chip connections.
The Registe MAP is in the area 03FF0-03FFFh only as a write option.
Here I have the original development documents from sks to the DISPLAY CONTROLLER for the KISS PC. A slight revision was made by TA for the alphatronic P2 series. And also used for the TA P3 / P30 systems.
Hardware (memory usage) and the software ratings are always almost identical.Display schematic / software parameters
In my revision of the MATRIX I have now the Ctrl function available
Via Esc key and another key, a Ctrl code is sent. That was exactly the same with TA. From the cp / m operation, this kind works properly.