Some EGI technical informations what I'm discovered:
It is a normal EXOS extension (header 06h), using own space as RAM at many-many points then it is can not placed to ROM.
The main activity started by load EXOS module function, the .EGI programs are 128 (80h) type modules which are handle by the EGI extension.
It is link a new device driver called as EGI: and also open channel for it, and set to default. This is a replacement of the EXOS EDITOR function for the graphical enviroment.
When writing to EGI: channel it is displayed in the active window.
For the mouse using a MOUSE: channel, which are come from the original Boxsoft MOUSE.XR, but any modified MOUSE.XR can be used.