I have started my DOSBox modding adventure, and of course am starting to have specific questions. Is it better to ask in this thread or start one over in patches or somewhere else?
My first question: as recommended, I've started by creating a callback. If I understand correctly, that will mean I can execute special opcode FE 07 #parameter and get to my callback handler code. But how do I know what value triggers my callback from dos code? And will it move around ever - obviously not, but??? I don't seem to set it up as part of the callback, coding by example, instead it gives it to me:
call_win3 = CALLBACK_Allocate();
CALLBACK_Setup(call_win3 , &WIN3_Handler, CB_RETF, "Win 3.x control channel");
Do I just see what number it gives me the first time, and hope it doesn't change? Sounds weird. But maybe my need to trigger this from a utility program is the problem, and I should build the "start windows emulation and load game.exe" into the shell? Or I could extend CALLBACK_Allocate to request a high fixed number instead of "the first available". Or am I being stupid and I just don't call Allocate and pick my own number? Any thoughts or clarifications?
Hm the deeper I get into this question, the more I just think I pick my own high number instead of/extending Allocate.
I also see an FE 38 "extra callbacks" in documentation, but I assume I'll ignore that. 😀