programmer, ZBasic Prodos memory usage map

I'm rediscovering ZBasic that was released, and as I was going through
the Apple specific appendix file (ZBASIC.APPENDIX.PDF), I saw the
memory usage maps on pages D-19 through D-21. Unfortunately, they are
completely unreadable. Does anyone have legible copies of these memory
map pages for ZBasic ProDos 4.2, 128k and 64k? I'd like to understand
where I can bload files into memory and call/use it later, without it
getting clobbered.

Thanks!

The best method for loading code/data is to define a variable or array
large enough to hold the code/data then use the variable pointer
function (see VARPTR) to return the code's location. Variables are
always stored in the main 64k bank of ram at the high end. It is
suggested to use relocatable code if possible but you can generally get
by with location specific code if you define the storage area as the
first variable in your code. It's even possible to share code/data
between chained programs as long as the variable definitions remain
intact. I've used this method in numerous ZBasic programs such as ATree
(a file manager utility). Sadly I don't have the source for Atree but I
did post a graphic block shape drawing routine with source code. You
should be able to find that on Asimov. Well, it's the source for the
routine but nothing to show calling from ZBasic.

If you look in the sample source I believe there is more reference about
this.

Sorry, I don't have my manual handy to check the actual memory maps. I
will try and locate it though.

Hope this helps.

Cheers,
Mike T

That's an excellent tip, Mike! Thanks. I'll check out VARPTR, that
sounds like a good way to do it. The manual did give a small address
range in page 3 that is safe to stash small ML code.
If you can track down those memory maps, I would certainly like to get
a copy. The first map in the series also has use zero page locations,
which would be handy.

Thanks again for the help,
Rich

I had my manual handy and a scanner, so I scanned the two memory map
pages you are looking for. I think this is the correct version... the
manual is dated 4/87 and is for the fourth edition. Please forgive my
notes on these pages. I marked off some of the zero page locations
(can't remember why... maybe they are reserved by ProdDos or
something?) and had a notation about the location of literal strings
in the memory map.

You can access the PNG image of the pages here:
http://dl.dropbox.com/u/381398/ZbasicMemMaps/ZbasicMemMap01.png
http://dl.dropbox.com/u/381398/ZbasicMemMaps/ZbasicMemMap02.png

Feel free to upload to Asimov or whatever. My copy of the manual paid
a heavy price scanning (binding started to break as I put it into the
scanner, and the pages are starting to fall out) so hopefully many
people can benefit from its sacrifice ;)