App Programming Help

ACagliano · Super-Expert Joined: 08 Feb 2010 Posts: 922

I have some questions about app programming...

1. If you have a 2 or more page app, and you are on page 1 and your data is on another page, can u still reference that data as you would in a typical program?

For instance...

benryves · Posted: 07 Feb 2012 10:34:28 am Post subject:

That would not work as written, as both pages occupy the same memory range and you can only address one page at a time. The easiest way to make it work would be to put the code to copy the splash screen onto the same page as the splash screen itself (page 1) and to bcall it from page 0.

graphmastur · Power User Joined: 27 Jul 2010 Posts: 464

No, this wouldn't work, or at least, not on the way you expect it. You would essentially have a routine outside of the 0x4000 to 0x7FFF range that would swap the two pages, copy the data you want in ram, and then switch back. Then, your code from page 0 could use it.

<I notice that benryves just ninja'd me>

Better yet, I would have the routines that use the same data on the same pages. Then, you don't have to copy, just swap pages, call the routine, swap back.

ACagliano · Super-Expert Joined: 08 Feb 2010 Posts: 922

Well, what do you have to do in order to swap pages?

Edit: and wouldn't it be call to the routine, not bcall?
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benryves · Posted: 07 Feb 2012 10:37:34 am Post subject:

Assuming you're using Brass, I suggest reading this tutorial.

Edit: bcall is used to call off-page routines, so you would need to bcall it. The bcall handler uses a branch table to swap in the correct page to call the routine, then swaps the original page back in when you return.

ACagliano · Super-Expert Joined: 08 Feb 2010 Posts: 922

Ok, and what would I put into de as the address of the LCD RAM? I don't think I can do fastcopyb from an app, right?
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