It's no secret I'm not a very good ASM coder, so erhm....I guess it's ok to ask a stupid question about programming, right? Some people say stupid questions don't exist, but I don't agree on that, so erhm....Shame on me now
What I always have wanted to know more about is interrupt programming. I've done some starfields out of sprites lately and the thing I did was diversing the hook at address #fd9f. I've put the old #fd9f content at the end of my source so it would be executed as well. Next I did a DI, PUSH'd registers and I worked through some coding using BIOS calls and the character table of sprites to make a movement. Then POP'd registers and an EI.
This starfield works nicely, but how much code can you execute in one interrupt is my question. ERhm....I do a DI, so there's no interrupt at all, right? But I slow down things if I put too many code to execute before EI again? And how does my program remember the content of the registers? Coz my starfieldprogram has to be executed from BASIC. I don't know how to put sprites on the screen, so I used BASIC for that. Hybride programming
It's just...You see I even have difficulties asking the question. I know I did some interrupt programming and it also works, but I don't REALLY understand the thing. Especially I would like to have some answers on the content of the registers and the amount of code you can execute during a DI.
Thx in advance and don't laugh too loud, will ya! :O