Jump to content
Sign in to follow this  

raster interrupt gets weird when I hold down a key

Recommended Posts

So, I have a raster interrupt that uses one sprite for two clouds, horizontally

independent of each other, with fixed vertical positions. It looks good until I hold down a key on the keyboard, then the interrupt doesn't work at all!


The sprite is a set of two clouds. After the first half of the sprite is drawn (the first cloud), the X position is changed, and the second half is drawn. But when I hold down a key, the second cloud is not repositioned (it reverts to the same horizontal position as the first cloud), so it seems to me that the interrupt is not taking place.


I'm a noob, so (as usual) excuse me if this is a silly question. :P

Share this post

Link to post
Share on other sites

Hard to say without seeing code but it sounds like you're using $ea31 to exit an interrupt at some point not far above the the split that's changing the sprite X position. An easy way to tell is to leave the runtime doing an inc $d020 / jmp *-$03 and you'll be able to see where the CPU is busy and what happens to that use when you press a key. $ea31 only really needs to be called once a frame so if every interrupt is exiting with it that will be using a lot more CPU grunt than is needed as well.

  • Like 1

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...