[Coco] Re: Newbie help: Barden Bubble w/ Portal-9

[Robert Gault]

jimcox at miba51.com wrote:
><snip>
> 
> Roger:
> 
> This actually clears up a few things for me.  I know this is documented 
> some place and I will eventually find it, but what is the specific 
> address range we should use with ORG in both Portal-9 and a real CoCo?
> 
> Jim
> 

There is no such range so it can't be documented. Safe addresses can't 
be determined without knowing what the program intends to do. I have 
written programs that use all 512K bytes of memory plus the ROMs of a 
Coco3. The only bytes not used to store code were I/O and GIME registers.

In general, an ml program should not overwrite any portion of memory 
where there is code that the program intends to access. If this sounds 
vague, think of memory as a very large chalk board where you have been 
writing equations. You need to get more of your ideas down on the board 
without erasing what is there. Also you can't write anything on the 
small space where the room light switches come through the board. So, 
you write wherever there is any unused board space. If it turns out that 
some of your equations are wrong or will not be used anymore, then they 
can be erased and new material written down.

If you tell us what you want a program to do and whether the program 
will be using any routines from a supporting OS, then we can tell you 
which areas of memory are free for use by your program.