Re: GS/OS Hires/Double-Hires File Recognition Problem

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

In article <4bepp5$ele@newsbf02.news.aol.com>,
RUBYWAND <rubywand@aol.com> wrote:
> 
>     Last time I checked, GS/OS (System 6.0.1)  still insists that "hires"
> files must be length $2000 and "double-hires" files must be length $4000.
> Most hires pics are length $1FF8 (to save a sector of storage under DOS
> 3.3);  and, some double-hires pics are length $3FF8.

I think you have some concepts confused.  GS/OS itself knows nothing
about filetypes (except special ones like directories).  Selected
toolsets (which are not part of GS/OS, but are part of the System
Software) know about file types that they deal with, such as the
various GS/OS application and related file types that are handled by
the System Loader toolset.

You might be thinking of Finder, which uses the "FType.Apple" file to
get file descriptions (and also other file type descriptor files in
Icons folders).  The rules in these files can match various
combinations of file types and auxiliary types, but do not pay any
attention to the file size.

Finder also uses other rules from icon files and bundle resources
(copied from applications into the Desktop file) to determine which
icon to display for a file.  The rules in a bundle could specify a
particular file size to look for, but this would only affect Finder,
not other programs.

>    This creates problems with painter programs (like Platinum Paint) 
> which use GS/OS criteria to decide if a file can be imported. For example,
> $1FF8 length pic files are not recognized as "hires".

If so, this is a problem with Platinum Paint itself - it is probably
looking at the file and deciding that it is not a hi-res picture
because the length is not $2000.

>    Is there a patch for the System 6.0.1 tool involved? (I think it is
> Tool 23.)  If so, where can it be downloaded? 

"Tool023" is the Standard File Operations toolset, which is used to
present the dialog boxes for opening and saving files.  It provides
several standard icons for files, and this can be extended in System
6.0 and later using the send/accept requests mechanism.

The actual selection of files to be displayed is handled by the
application, not Standard File itself.  The application can either
provide a list of file types and auxiliary types to match, or it can
provide a custom routine to check further information about each file.

In summary: if an application is not recognising a picture because the
file size is "wrong", then it is the fault of the application, not the
system software.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand