Re: ProDOS for 48k Apple ][+

[dempson@actrix.gen.nz (David Empson)]

Frank M. <frank_o_rama@hotmail.com> wrote:

> cool. thanks for the advice. i can write my sys program to fit in those
> memory constraints. are you still free to pass filenames and paths (ie.
> LOAD this file from CFFA) under prodos 1.0.1?

The only difference with ProDOS in 48K is that the kernel occupies a
similar memory area to that which would normally be occupied by
BASIC.SYSTEM in 64K, i.e. somewhere around $9600 and higher is used. I'm
not sure what the official method is to identify where the kernel
starts. It might use the memory map in the global page to mark itself as
reserved.

The MLI entry points are still in the $BF00 page as normal.

I have a vague recollection that ProDOS 1.0.x doesn't have the QUIT call
and it was added later. If it does, it isn't used by the programs Apple
supplied with the original system disk (each has its own user interface
to launch another application). At the very least, you can't locate the
quit code in the normal place, because it lives in an auxiliary bank of
the language card in 64K, which doesn't exist in 48K.

-- 
David Empson
dempson@actrix.gen.nz