These patchfiles patch from v. 2.3 to v. 2.2.
These are slightly involved to used because filenames changed.
They can be cleanly applied by going into the main ZCODE Patch directory
(the one with Makefile, zcdiff.c, etc.) and running the following commands:

cp history/2_3-to-2_2/*.patch .
patch -p1 < Makefile-2_3-to-2_2.patch
patch -p1 -o encrypt.c < zcdiff-2_3-to-encrypt-2_2.patch   
patch -p1 -o decrypt.c < zcpatch-2_3-to-decrypt-2_2.patch   
rm *.patch zc*.c

You will then have the v. 2.2 source files;
if you wish, you can then patch back to 2.1.