MSXdev23 #05 Super Ory 2 - Enigma

Nice! I love adventures!

I started to try it on FileHunter, however, and...

Illegal function call in 970.

I was on the first forrest screen, jumping around.

Hi Damned Angel, I checked where it said if the error occurred. I jumped over 100 times but nothing happened. Then I realized what could have happened. The line where if the error occurs is the subroutine that calls the sprites of the protagonist. It is made up of 4 superimposed sprites. Ory's sprites are 28 and a variable chooses them by adding or subtracting, according to the position they appear on the screen. It happened that the jump switch, doing it very quickly and continuously, interrupted the reading of the movement sprite going to read the jump sprite. These, having the same variable and being at a low value, went below zero and the error occurred. To give you an example: the sprites routine was reading the first sprite, which goes from 0 to 3, it was interrupted by the jump switch which, using the same variable and surely catching a subtraction, ended up below zero. That's why he gave illegal function. Unfortunately this happens with basic which is a slow program it would not have happened in ASM. But to console myself I say that it is a case in a million.
I hope you understood my speech.

It was not a disappointment indeed I thank you for pointing it out. I just explained why this error occurs. Had I noticed this during the programming period, I would have used another method. But I can't do it anymore because I have to change the structure of 5 programs and the thing is very long. As I said in the previous answer it's a case that happens once in a while, in fact with all the checks I've done it has never happened to me. Thanks again.

Great tip, I hadn't thought of that. I will do it. A thousand thanks

good