Re: XY on a Mac

[russurquhart1@xxxxxxxx]

I was led to believe that the later/last version(s) of Xy were written
in C. (Depending on the code, compiler and who you talk to, C can
approach performance speeds of assembly language.)
There was some discussion on this list a while back that someone had
access to the source, but nothing seems to have happened with that.
It is my conjecture that, IF the source for XY were accessible and it
was in C, then porting to other platforms would be easier. But still
not easy. Having not seen the code, i would suspect that the code would
certainly make use of certain MS-DOS function calls to do everthing from
accessing files to writing to the screen. (If this is in C, some of this
might be transportable, but it would all need to be looked at.)
I should also think you would want to be careful what you discard as you
would not want to break any existing Xy functionality.
Also, keep in my for the VPC users on Powerpc macs, part of the
performance hit on these machines is that VPC is emulating an Intel
based PC. Every command goes through this emulation overheard before
being executed.
Programs like VMware, running on an Intel Mac, by design, should have
less overhead because each command is passed directly to the Intel
processor, without needing any translating.
I wish the source for Xy could be found and resolved. While some may not
think having the source would provide much to the Xy community, I think
it would nice to try and get some interest in a port or at least a
slightly newer version.

Russ

On Fri, Aug 1, 2008 at 8:41 AM, Bill Troop wrote:
> > I'm guessing here, that what "porting" amounts to in practice is
> > writing XPL code and creating an API (application programming
> > interface). This is beyond me, . . . .
> sadly, it's beyond anyone else, too. For speed, XyWrite is mostly
> written in low-level assembly language, nearly the most primitive
> level on which computer instructions can be written. Very little is
> written like this today as it's simply too difficult. Assuming you had
> XyWrite's source code, which I don't think anybody on this list does,
> you would have to be a genius-level programmer and you would have to
> have a good year or two ahead of you.
> Anyone who actually wanted to bring XyWrite to another platform today
> would probably discard all the old coding and reverse engineer the
> program. I imagine that would take less time than re-coding. That
> said, now that Macs are on Intel, perhaps _some_ of the
> assembly-language code would still be usable?
> But there wouldn't be any point in revising XyWrite today except in a
> higher level language, because that's the only way it could be
> portable to multiple platforms present and future. The loss in speed
> through use of a higher level language would presumably compensated
> for by the increased speed of today's computers.
> > but I should think not unfamiliar ground for Carl and Robert. It will
> > require someone with intimate knowledge of XY source code and access
> > to a Mac.