Z-code Family Tree, portability, copyrights


Wed, 28 Jun 1995 12:02:10 -0600

I am currently working on a MagicCap port of a Z-Code interpreter. I was given a
significant head start thanks to the efforts of Rob Tsuk (rtsuk@meer.net) who
provided me with an already-ported V3-compatible set of source files (derived
from the ITF/Mac port). At this point, I'd like to consider which evolutionary
code path to follow and I'd like to get people's opinions on the direction of
Z-code, copyright issues, and portability.

The following information is based upon a preliminary crude analysis (as viewed
from a Macintosh perspective). I am hoping to elicit corrections from y'all in
the IF-community. My goal is to develop a free (in the GNU sense of the word, as
well as a financial sense) MagicCap implementation that derives from a
well-supported, evolving Z-machine source. At this time, however, I am uncertain
as to which source to derive from, ITF or ZIP.

Background
==========
It appears that the following portable Z-Code interpreters have been source-code
available for the last few years:
ZIP - Mark Howell (howell_ma@movies.enet.dec.com)
ITF - InfoTaskForce
There are also several ports of the source code that have not been integrated
into the main Zip and ITF distributions. Specifically:
Zip/Mac 8/4/94 Matthew Russotto (russotto@his.com,
russotto@eng.umd.edu)
ITF/Mac 1/10/94 Matthew Russotto (russotto@his.com,
russotto@eng.umd.edu)
MaxZip 1995 Andrew Plotkin (erkyrath@cmu.edu or
andrew.plotkin@cmu.edu)

Based upon the ftp.gmd.de archive, I have concluded that ITF is no longer
maintained by its original authors. I am uncertain as to whether Mark Howell
still exists and is actively interested in maintaining Zip portability; although
I assume he is.

In addition, Graham Nelson's Inform Designer's Manual has the following to say
about the subject [p. 65 in the 29/9/94 edition...Parentheses are Nelson's]:
The best-researched and most reliable interpeter available
by far is Mark Howell's Zip; as it's also the fastest, it
will hopefully 'take over' entirely. Next comes the
InfoTaskForce, which is thorough and should give no serious
trouble, but was written when the format was a little less
well understood, and so (in some ports) gets some (rare)
screen effects wrong. (It also lacks an "undo" feature, so
the "undo" verb automatically provided by the library
routines won't work under ITF. The other two
publically-available interpreters are pinfocom and zterp,
but these are unable to run Advanced games.

Conclusions
===========
I have a deep respect for Graham Nelson, Mark Howell and all the rest of the
IF-community who have kept the infocom technology alive, evolving, and in the
public domain. As such, the above Inform Manual's comment about Zip
'taking over'
carries a lot of weight. You gotta support standards and the public domain where
you can.

So, unless someone dissuades me or convinces me otherwise, I am going to
base the
MagicCap port on the latest Zip port that is unencumbered by copyright.

Sorry for the over-analysis, but I'd like to port the interpreter just once and
then have the forces of the Internet carry it into the 21st century.

-- 
Dan "Bud" Keith - dbk@odesta.com
  Once in a while, you get shown the light
  In the strangest of places, if you look at it right.