I have ancient serial terminals connected to a NetBSD 9.0. So far all works perfectly, except:
When I start an application software, this software switches the terminal's keypad to application mode, so the keypad cannot be used inside the application. After leaving this special application, the keypad mode is reset.
I guess the /usr/share/misc/terminfo database holds the information on how to switch the keypad's mode. But what to look for? Btw, it doesn't make a difference what TERM environment is set. Tried it with "vt510" (the physical terminal is a DEC VT 510), as well as with "vt220" and "vt100".
A hint on how to alter the termcap database was appreciated ☺ TIA!