Safe to use 32kb ram on MTX500?

Everything about programming, including VDP and Sound programming.
Post Reply
User avatar
Site Admin
Posts: 234
Joined: 09 Aug 2012 21:45
Location: Sweden

Safe to use 32kb ram on MTX500?

Post by Crazyboss » 12 May 2016 09:22


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

User avatar
Posts: 127
Joined: 12 Aug 2012 16:08

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.

THIS is what Memotech is doing now.

Martin A
Posts: 453
Joined: 09 Nov 2013 21:03

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.

Post Reply