Terry & Utahna <tolsen64@hotmail.com> wrote:

> Can anyone tell me what the Prodos Quit Code parms look like for quitting to
> another app?

There is no such beast, at least not as a standard feature on 8 bit
machines (or when booting directly into ProDOS-8 on a IIgs).

If you have booted a IIgs via GS/OS and are currently running a ProDOS-8
application, there is a variant of the parameter block which is
supported for doing an explicit "quit to application" - probably known
an extended quit.  (It is actually implemented by the GS/OS quit code.)

I'd have to do a fair amount of hunting to find the documentation, but
my memory suggests that the parameter block should be something like
this:

quitparm
        dfb     $04
        dfb     $EE             ; EE for "extended"
        da      pathname
        dfb     $00
        da      $0000

pathname
        str     '/volume/application'

If you try to use this method while not booted via GS/OS, it will do a
normal quit to the program selector.  It also won't work if something
has replaced the GS/OS quit code with a third party program selector.

The only 100% reliable way of quitting to an application is to write
your own code to load it directly (OPEN, READ it to $2000, CLOSE), and
jump to it, after restoring any standard environment that is expected by
a newly loaded SYS application.

-- 
David Empson
dempson@actrix.gen.nz