Re: Questions on launching Prodos Program from GS/OS

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

Oliver Schmidt <ol.sc@web.de> wrote:

> In fact I have a IIgs (with one 3,5" drive) but as I even didn't get
> GS/OS up and running in KEGS, I didn't work on the additional
> difficulties off transfering the stuff to my IIgs. And to be honest
> the time to invest into the Apple2 is very limited for me so I didn't
> want to invest much into GS/OS when I'm actually into writing a ProDOS
> 8 application.
> 
> In case you can understand this attitude it would very nice if you
> could answer some additional questions...
> 
> Is it plausible to assume that advanced GS/OS users are able both to
> create Icon files and patch file types?

You shouldn't be getting end users to patch your files to have a
specific file type and auxiliary type - you should supply them with
these values already set.

In principle, a particular combination of file type and auxiliary type
are supposed to be allocated to an application to uniquely identify its
documents. The problem is that Apple isn't running the registry any
more, so we're back into the bad old days of risking stepping on each
others' toes. The best option is to try to pick something suitable and
ask whether anyone else might have used it already.

The file type is supposed to indicate the general class of document, and
the auxiliary type is typically a specific value allocated to your
application. Look at the existing types in FTN.About for examples (and
for documented reserved combinations). This list is by no means complete
- Apple DTS had a much larger list which they never published.

As for the GS/OS icon file, you might be able to find a friendly
advanced IIgs user with the right software to create one for you. (My
IIgs is not accessible at the moment so I can't help.)

> As you may guess by now I'd really like to withdraw from all that GS/OS
> specific stuff and just support the ProDOS 8 startup document procedure
> mentioned above. The "documents" in question are about 20 coming together
> with the application without the option of creating additional ones.

How do you intend to get end users to invoke the application with a
particular startup file under ProDOS-8? Are you going to require the use
of a shell which supports the startup protocol?

> Is there a freely available tool running under ProDOS 8 for modifying
> the file type of a given file?

Probably, but I don't recall using one. I was using the IIgs before
auxiliary types were all that significant, so I always used
IIgs-specific tools to manipulate the file type and auxiliary type
(probably a command line tool under APW or the ORCA shell).

The basic mechanism is available in P8 via a SET_FILE_INFO call to the
ProDOS-8 MLI, so you could do it with a short machine code routine under
BASIC.SYSTEM: do a GET_FILE_INFO, patch the necessary fields, then
SET_FILE_INFO.

-- 
David Empson
dempson@actrix.gen.nz