View source for Z-machine versions

There are at least 10 different versions of the Z machine out there:

* Versions 1-6 Created by [[Infocom]] in the 1980s.
* [[Graham Nelson]] made some minor changes in the 1990s to allow for larger story files, creating versions 7 and 8 of the spec.  Most, if not all, modern [[Z-machine#Assorted_Z-machine_interpreters|Z machine interpreters]] support z7 and z8 story files.
* Adventures which are too big for even z8 can use Andrew Plotkin's [[Glulx]] virtual machine, which has been around since the early oughts (first 2000s decade).
* In 2013, Zzo38 created versions 9 and 10 of the spec, with a number of extensions allowing even larger story files, finally giving Z-machines XOR support, and many other changes.  These versions are not described in the 1997 [http://mirror.ifarchive.org/indexes/if-archiveXinfocomXinterpretersXspecification.html Z-machine specification] 1.0 nor in the 2006 [http://mirror.ifarchive.org/if-archive/infocom/interpreters/specification/ZSpec11.txt Z-machine specification 1.1] (the most recent version); the only known [[Z-machine#Assorted_Z-machine_interpreters|Z machine interpreters]] that support these versions are Zzo38's own [[Aimfiz]] and [[Fweep]].

==XOR support==

v9 and v10 story files give Z-machines XOR support by defining the [http://www.gnelson.demon.co.uk/zspec/sect14.html#2OP 2OP instruction] 29 (1D in hex) as being BXOR, with works like BOR or BAND, but performs a binary exclusive OR operation.  Note that [[Glulx]] has always had XOR support ([http://www.eblong.com/zarf/glulx/glulx-spec_2.html via the "bitxor" operation]).

==Links==

* [http://www.gnelson.demon.co.uk/zspec/sect01.html This describes the non-Infocom extensions for versions 7 and 8 of the Z-machine]
* [http://hansprestige.com/inform/zmachine_versions.html This compares versions 1-8]
* [http://zzo38computer.org/zmachine/z9.txt Spec for version 9 and 10 of Z-machine files]