Re: Disassembling an FST...

[Paul Schultz <pschultz@med.wayne.edu>]

On 15 Sep 1998, Supertimer wrote:

> Paul Schultz <pschultz@med.wayne.edu> wrote:
> 
> >It has been well documented here on csa2 in the past that the reason
> >there is no FST specs/docs is that the interface between the FSTs and
> >GS/OS was always modified whenever there was a new FST introduced.
> 
> Or so Nathan always claimed.  ;-)
> 


The discussions I refer to occurred with Dave Lyons and Jim Murphy at
the time that System 6 came out. They have nothing to do with Nathan.
Although the info he provided on this topic is correct as I recall.


My comments on non-standardized GS/OS - FST interface removed...

> 
> Theoretically.  However, the HFS FST actually does work if you
> put install it on System 5.0.4.  Apple made some very scary
> warnings about doing it, but I have done so in emergency
> situations without harm.

This may be true but really isn't the point. The folks at Apple wrote
each version of GS/OS to optimally fit the current FSTs at the time.
While a newer FST may indeed work with older versions of GS/OS it was
made quite clear that this did not mean that the interface between
GS/OS and the FSTs is clean enough to simply disassemble one FST and
assume you have the entry points/hooks to allow you to successfully
write or improve other FSTs. For example, if you were to disassemble
the HFS FST in the hopes of adding support for HFS+ or even to use
it as a template for another FST, it very likely wouldn't work since
the entry points into GS/OS were very specific for the particular
FST and what that FST needed to accomplish.