Safe to use 32kb ram on MTX500?

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Crazyboss
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Safe to use 32kb ram on MTX500?

Post by Crazyboss » 12 May 2016 09:22

Hi.

Is it safe to use all 32kb of ram on a MTX500, I am thinking to load one part of the game into vram and the other part into lower memory from 8000-> and then move the data from vram to higher memory. But would it be safe, what about Interrupts, buffers and System variables is it safe to overwrite them?
//CLAUS - Webmaster at www.mtxworld.dk

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thewiz
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Re: Safe to use 32kb ram on MTX500?

Post by thewiz » 12 May 2016 10:28

Hi Claus,

You probably don't have to worry about the BASIC variables at $c000, which is normally a single $ff anyway if nothing has been defined.

System variables are from $f8f2 up to $ffff.

If you are not using Basic interrupts, but your own, then I would say issue a "DI" in your code and copy away.

Note the interrupt table is at $fff8 if you are thinking of overwriting system variables with your own copy of system variables, then I wouldn't worry as the tape load rom routines do that anyway.

Regards
THIS is what Memotech is doing now.

Martin A
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Re: Safe to use 32kb ram on MTX500?

Post by Martin A » 12 May 2016 10:30

If you don't use any ROM routines then the memory used by the system variables is free for use.

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