Re: Questions on launching Prodos Program from GS/OS

[Oliver Schmidt <ol.sc@web.de>]

Hi David,

First of all thanks for your detailed answer :-)

>> Maybe my question wasn't precise enough. In fact my question is: Is it
>> correct to assume that there is always a 64k /RAM device at the point
>> of time when GS/OS booted into ProDOS 8?

>[Detailed discussion on how to deal with /RAM the "right" way]

Thanks but I was aware of all that already.

>On a standard unpatched IIgs system, the first launch of a ProDOS-8
>application from GS/OS should always have /RAM present and it should be
>empty.

That is the info I was looking for :-)

>If it is disconnected while P8 is running and then there is a
>quit (back to GS/OS) and a subsequent relaunch of P8, is it possible
>that /RAM might still be disconnected? I haven't looked into the innards
>of the GS/OS-to-P8 connection to know this, but I expect /RAM will cease
>to exist and will then be reconstructed (empty) when P8 is relaunched.

I see.

>See ProDOS-8 technical note 26 (Polite Use of Auxiliary Memory).

As this is available online I'm aware of the content. Thanks anyway.

>The GS/OS Reference doesn't appear to explain whether GS/OS supports the
>ProDOS-8 SYS file convention for opening a startup document (by patching
>it in to an identifiable data structure just after $2000)

...that's what I refered to...

>but I'm pretty
>sure it can launch Applesoft BASIC files via BASIC.SYSTEM, so it should
>work with other applications as well, given a suitable icon file which
>identifies the file type and auxiliary type as belonging to your
>application.

Basically that's what makes sense...

>> I don't have access to a running GS/OS installation. Could you please
>> elaborate on this? Especially on my question above. Has associating of
>> data files something to do with file types, file name schemes or is it
>> a file-by-file approach - as I understand from your remark above?
>
>File names are not used for document association with applications.

That's what I assumed form what I read about later Apple OS's...

>The file type and auxiliary type are used to identify which application
>should be used to open a particular document. Icon files (located in the
>Icons directory in the root directory of any volume) are the method used
>to specify this information, and also associate an icon with the
>document and the application.

I see.

>You would need a IIgs and the appropriate
>application to create these, but you could try creating one by hand as
>the file format is documented in the Apple II File Type note for file
>type $CA (FTN.CA.XXXX). You should also read FTN.About for general
>guidlines on file types and auxiliary types, though I doubt Apple is
>assigning them any more.

Well, I wasn't aware of the 'Apple II FIle Type Notes' at all. Thanks
for the hint :-)

>There are also the File Type Descriptor files (type $42) which are used
>by Finder to describe file types in human readable form. These are also
>documented in a file type note (FTN.42.XXXX).

I see.

>It might be easiest to get hold of a IIgs from somewhere.

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? 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.

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

Again thanks, Oliver